I do not think that the Hero Factory Brain Attack sets were that bad. In fact, I think they look a lot better than the BIONICLE summer 2016 beasts.
I hate that BIONICLE G2 did away with the Toa's original unique mask powers from G1 and replaced them with the Toa's elemental powers.
I think G2 is slightly overrated. It isn't necessarily bad, just not that outstanding like some people seem to make it out to be.
Hero Factory is underrated and not as bad as people make it out to be just because it filled in for BIONICLE after it was cancelled.
The Beasts are some of the most overrated constraction sets of all time and are just mediocre at best and... crude and unfinished looking at worst. People praise them for their unique functions which, again, aren't even that great and are pretty meh in person.
I feel as though people only like the Beasts because they have functions and the BIONICLE name slapped on them and if they were Hero Factory sets without functions people would despise them.
I loved the Hero Factory villains and enjoyed them along the BIONICLE G1 villains a lot more than the BIONICLE G2 villains both set-wise and story-wise and think both are better overall in my eyes.