Feel like skill trimming is also becoming a factor in this as well, devs seem keen on keeping the amount to a certain number prolly for controller users, but... that in turn simplifies the jobs a tad. I'm sure they're going to continue doing it every expac as well so there may be a day where things end up being like single button combos and such. Also got to keep in mind that devs try to please as much as possible but when push comes to shove, they'll almost always go for the larger group of folks in need, and the number crunching hardcore players are fairly small compared to the rest, not to mention western mindsets can be pretty different to the JP community, so it's a very difficult job for the devs.