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.