(replying to your reply below, which is at max comment depth)
None of the other self-traders you identify are running full time bots as far as I know. Thus they are not always stacking the queue and preventing (at least currently) smaller liquidity providers from ever being paid as yours does.
If you were to pull back and if it turned out that actual liquidity providers were still never paid (and thus encouraged to continue and even expand), then it would be reasonable to resume what you are doing. But there is no way to find that out without trying.
There are many names on that list who are not being rewarded even though they have likely provided liquidity to the market and would likely do so again if rewarded for it. Providing liquidity also becomes easier for others if they are receiving rewards (even occasionally) since there is no other good way to have access to liquid steem without incurring an opportunity cost.
The most successful tit-for-tat strategies will forgive occasionally to attempt to test a return to a cooperative equilibrium. That is my suggestion.
Thanks for the reply. They were running full time bot before I started to compete to them. I have no idea whether they'll start do that again if I stopped, it's fair to assume they will. If they want to show me that they won't do that again (sounds like I'm police), they can reset their reward points by self-trading on the opposite direction, then I'll remove them from my "bad guys" list manually, and start to compete "normally" . Anyway I don't think it's bad to set a barrier.