I'm going with plagiarism, though it also might be due to ban evasion.
During 2017 you used a lot of copy/paste lines to join bounties. Some of the accounts they were copied from look like they could have been your alt accounts, and many of them have been banned. It's possible you were just using the same list of copy/paste responses they were.
Interesting and promising project ,, I've joined bounty twitter .. please update spreadsheetnya soon .. hopefully this project succeed and develop quickly ,, so that it can reach the highest level in stock ,,
I joined bounty twitter ,, i will support this project till the end .. hopefully this project succeed and develop quickly .. good luck dev
very good project and interesting .. I am incorporated in bounty twitter .. hopefully this project will be successful and will reach the target that has been planned .. good luck dev
Very good project .. hopefully this project will be successful and will reach the target that has been planned .. so that can attract more investors to join in this project .. good luck dev
very good project and very interesting .. i joined bounty twitter and facebook .. hopefully this project will be successful and will reach the highest level in bursa .. i will support this project till end of ICO .. good luck dev
Very good project .. hopefully this project will be successful and will reach the target that has been planned .. so that can attract more investors to join in this project .. good luck dev
There are dozens of other examples just like these ones. Most of the people who engaged in this kind of copy/paste have already been banned, but you slipped through the cracks for quite a while. I know it was 3 years ago, but rules is rules.