It looks like double standarts. There a thousands of bots that posting nothing, but airdrop-bounty reports, and pumping merits with no ban and so on.
Sure. There are probably other bots that are committing plagiarism that are currently not banned, but is it really a valid reason to not ban you just because some are yet to be caught? I don't think so. Also, while posting solely on bounty threads is definitely frowned upon here on bitcointalk, it's not entirely illegal.