Speculation:

Bad reception for the same reason parsers are - visible, semi public source of how well you perform by seeing whether you die to the boss or not and how active you are in a fight.

Good intention regarding improving performance never gets good reception to the point that any attempt to give such tools is greeted with hate and speeches how SE deceived them. At this point the term "improving" has been villianized.

As said, merely speculation because it is not the first time hypercasuals made a lot of noise to anything that could urge them to up their performance a little (minor dps checks in casual content, god forbid).