Are there any people who did not trade actively and still got banned?
I suspect that they banned accounts that were suspected of price manipulations or part of manipulating syndicate groups, or people with multiple accounts. Cointelegraph says that more than 3000 accounts from Iran have been suspended. But do you believe that Iran may have 3000 trading accounts on Bittrex? ...
I don't see why Bittrex or any other exchange would be concerned with price manipulation. The more volatility - the more profit for them.
Also, you don't need multiple accounts to manipulate market. You can do the same with one account that you can do with 3000.
The suspended Iranian users as they were afraid of legal consequences of providing financial-like services to restricted countries.