Why does BHVR keep trying to nerf ""potential"" A tier killers?

I've noticed this for a long, long time but the two cases that stand out to me the most are the Harmless Unknown and most recently, Wesker, which makes me curious because why would either of those two ever be considered for nerfs when they've slowly and surely been getting power crept as time has gone on? People like to put both those killers in A tier usually, but I never really agreed with that sentiment.

There are strong A tiers, like Pyramid Head, Singularity, etc and then there are "potential" A tiers like Wesker and Unknown. Strong A-tier killers are almost always consistent throughout their matches, not requiring that much RNG to sway their chances of victory, whereas potential A-tier killers suffer massively when they get a map that isn't in their favor, and or survivors who are very aware of what they can do and can properly counter them. The Unknown, for example, can be pretty good IF you somehow never miss a shot ever, get a decent map, and get survivors who don't know the proper counterplay to him, because otherwise he feels absolutely miserable to play. Wesker can be really strong if you get a map that isn't absolutely cluttered with objects or weird collision, and or go up against survivors who don't know what he's capable of with his techs because otherwise, once again, he feels incredibly weak at times with his infection no longer being a serious threat and his power not being good for map mobility. So with all that being said, what's the deal with these types of killers repeatedly catching strays that the community then opposes strongly?