Is anyone really running out of allowances? The leves are so boring and repetitive that I can't comprehend how somebody would spam them over and over.

You can cap ANY crafting class even with 100 leves in a week. I know this because I capped my CUL BSM and CARP in a week each. Suggesting that leve limit somehow thwarts your leveling progress is nonsense. Especially now that we have engineering manuals that literally make even the last levels breeze by.

I always thought that the cap is just there as a back up plan should the game ever go free to play.
It's exactly the kind of wait-to-play tactics f2p games use and as such has no use in any other kind of a game.