Nah, you need to stop looking at it as something inherently bad. You are just awaken your fruit like everyone else does, it's always a PU and losing someone's mind would be a ridiculous drawback, as it really does not help the user one bit.
The wardens were most likely just fodder that got their lineage factor artificially changed, basically like a permanent pre timeskip Monster Point.
Why are all those Beast Pirates not awakened? Cause it's too powerful, relatively. Every Yonkou Commander always wields strength relative to their rank (Veteran, F6, Sweet Commanders, Calamities).
-> Just assume for the moment that Zoan awakening is indeed some kind of monster form and now you want to have guys like Queen and King overall as strong and not really stronger than they canonly are, their special quirks -cyborg modifications and lunarian abilities- would have to suffer a lot as a consequence.
Same with the F6. The way they are now, they all would probably end up as YC3 lvl guys with awakening, if not even stronger, so in order to not have them that strong, which simply has to be, Oda would have to downgrade them heavily in other parts, which does not necessarily help the story at all.
