I really am not one to start threads on lodestone, but I think the materia system is a great idea that should greatly be expanded upon. Currently you only get materia from spiritbonded gear, which isn't a bad idea but there should be other, more engaging, methods. Also the variety of materia should definitely be increased. So here is my general idea for materia, or at least the expansion of materia.
1) Unique/Rare powerful materia from special bosses
I'm not talking about the same lame att/matt/acc stuff. I'm talking things like Haste/att speed, TP generation increase, special WS's for each job, or special add-on effects to existing WS's, etc. These should be stupidly hard and time-consuming to get, of course. But this would add a sort of "treasure-hunting" aspect to the materia system..which i'll get to in point 2.
2) Reward exploration with materia
I think the great thing about Final Fantasy x-2 was the whole "treasure-hunting" thing. I'd say of those that actually played it, having to search for things was a strong draw..that and the win combat. I see materia as waht separates beastly from good, and as such it should be a bit more prevalent. Hide materia in dungeons, add materia for certain quests, add materia fragments spread throughout eorzea and combined into one strong materia..lots of potential here. It adds both a market (for tradeable ones) and a storyline (materia hunters anyone?). I just find it weird that materia isn't more talked about in eorzea.
3) Materia should be something like a specialty. This is a hail mary idea, and admittedly not a very good one in its current form. But imo socketing materia should be a bit more involved than rolling the dice. Seems kinda, tacked on to me. Of course adding a crafting class specifically designed around materia would anger a lot of ppl. I understand that. The socketing process, imo, needs depth..either through a new class or as additions to existing crafting classes. Maybe even salvage materia? Combine materia to make new materia? Hiding different combinations could give ppl a lot to do and discover. In any case I digress.
I'd like to hear other players' thoughts on the materia system. I think it should more or less be the basis of the combat system/balance, and as such should be given more depth and importance. I doubt a dev will read this, but it'd be interesting to see how players look at materia and what it could be.