When I mention core content I meant more just this pattern of patch releases and the content featured in it that isn't extra like Diadem and so on. not the core way the game mechanics function or anything of the sort.
My issue with the way savage and EX Primals are structured is that unless you're going for absolute BiS there's no incentive to do them. In the case of EX Primals there's no point because tomestone gear outscales it (Shinryu aside but this will be the case again in 4.2). In the odd catch up patches you can just spam 24 mans until you're 340 with all tomestone gear from weekly drops of upgrade materials. There's little incentive to tackle the hardest content in the game outside of savage because the easy way out is always there (tomestones). I personally have an issue with the roulette grind myself but I know they've implemented other ways to get tomestones which is a plus.
Since you mentioned getting better as a player, I actually picked up Paladin to play this expansion when I've played Ninja (and held my own in an ok-ish manner) since I started back in 2.44 to shake things up but even then I don't feel any incentive to gear up and tackle savage because there seems to be no point... I can do 4.2 content just fine in 320 gear with a tomestone weapon and I personally don't have time to do anything but PUG Savage and, besides Shinryu, the EX Weapons are useless because I can get a shiny 330 weapon if I wait long enough. If I bide my time I can just sit on a 330 weapon and upgrade it to 340 in the next patch so no point in doing Shinryu. The thing I enjoyed when I came to this game was the feeling of progressively getting stronger with each challenge but after figuring out how the system works I don't feel any incentive to tackle these challenges and I'm sure I'm not alone in this sentiment.
My other issue I guess has to boil down to replayability. A lot of the time you see people log on for maybe two weeks then just stop outside of weekly drops from savage, 24 man, etc. If they're BiS good luck seeing them log back on until the item levels go up or Bahamut Ultimate comes back unless they want to gear up other classes or level them up.
So when I mention to change the way core content is structured and delivered I guess it's more about improving the incentives to tackle this fun and challenging content and give us core content (dungeons, raids outside of savage, etc) that draws myself and other players back for more. So it doesn't feel so old hat so soon.