There are a lot of issues with the bot tracker, it is far from perfect. But buildawhale is and has always been a "bid bot." The data you are sampling is incorrect. I do not have time right now to analyse your results but when I can I will. There are other factors at play too that you are not considering.

He is giving a fixed return instead of giving a propotioanal upvote. This is violating bid bot manner as I mention above.

He is not giving a fixed return as if you watch all windows buildawhale is often in the positive. If it was fixed it wouldn't wait until 100% and rather would bid as votes came in.

He also change the time frame. This is violating bid bot rule.
So buildawhale should be removed from bid bot list.

The time frame hasnt changed rofl, there are a few reasons it can get extended and its not always exactly the same. And what rules do you speak of? An unwritten code of some sort? I know the owner of Buildawhale pretty well and I see no reason to think that he is doing anything that could be considered violating any of such rules you speak of. B/c of what he does with spam you can bet that you are more likely to make ROI from buildawhale over ANY other bot.

Consider to critique the other bots and you will see the difference and benefit of using @buildawhale over anything else.