A couple of points about BST.
#1 They don't all MPK... Just because you saw 1 or 2 high level BSTs MPK they doesn't mean they all do. Most high level BSTs, and I don't mean mid 50s but more like mid 60s-75, carea lot about their reputation because rep is probably one of the most important things in this game especially endgame.
#2 Often people are retarded and think they are being MPKed. This most often happens in the 50s while leveling in Garlaige because the best pets (beetles) are down the hall from the best XP mobs (Bombs) Generally BSTs like to just XP safely in said hall but PTs seem to not care and tell the BST to leave even if he has been there for a while.
If it was a PT you would think it rude to camp on top of them but for some reason peopel don't feel the same when it's a BST. If the BST continues to XP there it is very likely that the Bombs it is fighting will explode and kill the PT. If the XP PT starts XPing off of the BSTs pets (beetles) and the BST cannot get back to his pet you are basically MPKing the BST.
#3 Do not blame the BST that you are getting minimal XP off of his released pets. If you would just be nice and not steal his half health pets you wouldn't have to worry about it and perhaps you could even co-exist. Remember... if you are bitching about crappy XP from his former pets it is you that is being rude for stealing.
#4 BSTs cannot just go elsewhere. BST have to find a very specific area where they have mobs in a charmable range and mobs in an XPable range together. Just because you have not understanding of the BST doesn't mean you should just tell them to leave their XP area because you think they are so much more flexible than a PT.
#5 Pets do not hurt XP of the PT... only that of the BST. For BSTs past 35 with release this isn't even an issue so in all honestly inviting a BST/WAR or BST/NIN is great for XP. They are some of the strongest DDs in the game by a large margin. The only way PT XP will be affected by BST is if the mob they charm is high above them that it is basically higher than the highest member of the PT which is not likely because BSTs don't generally go around charming Ts and VTs.
Now it sucks when one BST is a [img]/xxx.gif[/img][img]/xxx.gif[/img][img]/xxx.gif[/img][img]/xxx.gif[/img] and does retarded crap like this. In my experience it is mostly mid-range BSTs played by someone as a secondary job that level it just for the MPKing ability but if you will be kind to them a BST will be very good to you. They can save your ass in a way you can only imagine. I have XPed in PTs with BSTs and gotten amazing XP. If we got a link their pet to could keep it occupied for quite some time or they could charm and release the pet far from camp. A BST/NIN can do damage on par with a WAR/NIN with good gear and add their pets and especially their pets TP moves and you basically have a 7 member PT.
Do yourself a favor and burn the brady guide or at least the second about jobs because it is rubbish and go invite a BST to your PT if you are lucky enough to get one ^^