Siddharamaiah Government (aka Congress Government) ripped itself from the Throne however after amassing lot of wealth to its colleagues. Below are alleged Scams that the Congress might have committed during its reign.

1. The Construction of the roads in Kempegowda layout has have a major scam resulting in almost 43 crores per km whereas even the most international quality road construction will only cost 4 crores. Rs 43 crore-a-km spend on Bengaluru arterial road raises eyebrows - Times of India
2. Steel flyover proposal which was an abject waste of tax payer money which was a ploy by Congress to raise funds for next 2018 elections Protest against the first steel flyover in Bengaluru
3. Scams in Borewell during the Congress government in 2018 in Karnataka https://www.thehindu.com/news/nat
4. Government of giving tenders from the Karnataka Slum Development Board to select contractors resulting in corruption of more than 2500 crores. Congress got kickbacks in Rs 2,500 cr 'commission scam', alleges Karnataka BJP
5. CM and Power Minister involved in scams of upto 450 crores. Karnataka CM, power minister involved in ‘Rs 447 cr scam’: Yeddyurappa
6. Karnataka Fisheries Minister Pramod Madhwaraj accused of bank fraud Karnataka Fisheries Minister Pramod Madhwaraj accused of bank fraud
7. The Karnataka CM Siddaramaiah itself under serious corruption charges Karnataka CM Siddaramaiah under scanner in 'Rs 688 crore mega garbage scam'
8. George Home Minister named in forcing an IPS Officer to suicide when he refused to be corrupt Karnataka Minister K.J. George Named In CBI FIR Over Cop's Death, CM Rules Out Resignation
9. George Minister in Cabinet involved in Illegal Land Deals Karnataka home minister KJ George's company linked to illegal land deal
10. George owns large swathes of real estate across Bengaluru, where he has built several software parks, earning tens of crores a month in rent. He lives in a top-end pent House at the Embassy Golf Links on old Airport road, with a private Golf Course and five star hotel as part of the residential compound.
11. Names of Karnataka chief minister and health minister have emerged in the condom scam. Instead of buying condoms from government agencies, they were purchased from private companies and were reportedly distributed on paper only. The government has not revealed the data of money spent on condom distribution and treatment of AIDS Karnataka govt hit by Rs 500 crore condom scam; CM, ex-health minister named
12. There are 43 complaints of corruption against Karnataka Chief Minister, Siddaramaiah pending before the Lokayukta. However Lokaayukta has been made weak and thus none of them have progressed.
13. Shocking scams of Karnataka Congress Government that has surfaced. Documents of the Anti Corruption Bureau highlight Siddaramaiah's government fleecing the municipal body in Bengaluru to the tune of Rs 68 cr. The hoardings of nearly 439 bus stops of Bruhat Bengaluru Mahanagara Palike singing praises of the government's welfare schemes and achievements have been exploited and not a penny paid

One Quora user writes this possibly the reason of distrust among urban voters

1.Metro was started long long long ago by someone not at all related to Congress, Please google it, construction infact has slowed down during Siddaramaiah rule. The current rate of construction is 1.5Km per year and completion is expected by year 2032. Ref: Cut to 2032: Namma Metro work will still be in progress - Times of India

If at all there is water left in Bengaluru, people will be here to use metro in year 2032 . With no strict measures for rain water harvesting, I doubt people will be there in Bangalore by 2032.

2.Bangalore is home to blue chip companies because of the actions of past governments, this has nothing to do with Siddu sir,

3.No initiatives taken by Siddaramaiah to generate power till now. All Karnataka govt is doing is buying power form center and neighboring states. Central NDA govt recently increased the capacity of the grid from North to South. Now Karnataka can buy power form other northern states easily without increasing generating capacity.

4.IT came to Bengaluru, We should all Thanks to S.M. Krishna who was a very powerful magnet to attract all companies which are here today. Growth in IT business has nothing to do with Siddramaiah government. Siddaramaiah has failed to provide proper roads to reach whitefield, Metro construction has not even started in Whitefield. Recently couple of companies left Bengaluru and shifted operations to Hyderabad. These companies said its employees are wasting 3 hrs daily for travel. Its a Utter failure by Siddaramaiah government which as failed to address traffic and infrastructure issues faced by IT sector.

(if somebody thinks current CM has done some thing for IT sector, please come have a look at the roads in Whitefield, The traffic, the chaos every software engineer is going through every day to reach office and come home. This is pathetic condition to go through every day. Tentative date for metro construction towards Whitefield is July 2016. When will whitefield (IT destination) gets metro if construction itself has not started yet)

5.Congress has numbers this time, so there is political stability. Thanks to Yedyurappa for forming KJP and dividing BJP votes. Now Yeddi is back to BJP, next time we will see real Congress 's numbers

6.Some powerful minister threatened cable operators in Karnataka to stop telecase of TV 9. This is biggest mis use of power I feel. Reference: TV news channels blocked in Karnataka over sting against a controversial minister DK Shivakumar

7.Inspite for such a good revenues for Karnataka government. They asked for a package from center. Sad that Center also did not come to rescue.

8.Start ups prefer Bengaluru because of the pool of IT Talent here in Bengaluru, not for anys sops given by Siddaramaiah. Again thank to SM Krishna for bringing IT, nothing to thank Siddaramaiah

9.Government has failed to tackle corruption which was taking place in anti-corruption cell "Lokayukta" itself. This was the sickest thing which has happened ever since.

10.Peace and tranquility is there because people have jobs, not many are dependent of money given by politicians to start a fight. Again thanks to previous governments including SM Krishna (for bringing IT which has given jobs to so many urban and rural Karnataka people). No contribution by CM Siddaramaiah here.