Buying votes removes the proof of brain consensus. Marky was one of the few that actually cared about the quality of posts his bot voted on, and removed votes for low effort/spam posts voted by buildawhale.
I am also under no illusions that Marky is perfect, and out of the thousands of accounts blacklisted, I'm sure there were some that weren't as worthy as others. What I do know is if I were to get blacklisted, spamming obscenities and threats wouldn't be the path I would personally choose to get the matter resolved (not saying you did this, but I've seen it happen over and over). Reasonable people are more likely to be met with reason, and emotional people are more likely to be met with more emotion.
Whose steem got burned?
FTG's steem didn't get burned. He sent it for a vote, and the vote was given, then taken away because it didn't meet the standards for buildawhale. However, the voting power he paid for couldn't be magically returned, since it was used for a post, so technically it was Marky's to burn.
I will say that the ToS of buildawhale could have been better, such as making users agree to the terms before they could ever use the bot, but the fact of the matter is those were the longstanding rules of the bot, and like it or not it's how it was applied to everyone, not just FTG.