Beastmaster was underpowered for a long time pre-abyssea, those of us who chose to level it had to learn the intracacies of Charm and mob families. I agree, there are a lot of Perle BST's who burn the job to 99 just to do dyna. In level 75 endgame they can do pretty decently, as can a lot of other jobs. However even a well geared BST has issues with the endgame introduced since abyssea.
Pet's have already had a couple of nerfs in the last year or so, there was the pet PDT nerf last year, which in hindsight made sense, as being able to get 100% PDT on pets was probably a bit broken. We have also had the TH nerf not so long ago.
My BST doesn't get as much use as it used to, currently the main uses are in Salvage and in Dyna.
I believe that the newer stronger pets were introduced because Charm was made virtually useless in anything Abyssea and onwards.
All jobs can be played well, or not so, gear contributes to this a bit, but a lot of it is the player themselves.
Asking for a nerf, just because BST can now solo old content doesn't make much sense to me. I think things are OK as they are currently.