As I said, the game is already built with interdependencies in mind, but some of those interdependencies are an annoyance. FFXIV have a wannabe sandbox crafting system "too complex" for a theme park and to simple for a sandbox (no decay and all items are the same outside NQ/HQ).
Interdependencies are nice when are well done but that it's not the case, the market spin around materials (like ores, crystals) or complex final products, the rest has no value. Why bother selling Aurum Regis Nuggets when is more profitable to sold those materials? This problem is common to any MMO's that allow players to have all the crafting professions in some way, you either sold rare materials or final products from rare recipes. (Yeah, I know there is a market for HQ Leve quest items).
Back in games like Ultima Online or Star Wars Galaxies this never existed, everyone needs something from others but crafting skills were fully independent (not like CRP, for a lot of his recipes the least material used is wood

).
BTW, I did not mention that the economy is dead but NA/EU server are in bad shape due to gil sellers, this is especially noticeable in "small" servers where anything is unaffordable from no crafter/gatherers, even raid consumables or basic tools (my main reason to level DOH/DOL).
So I don't see the point to force a player to level all crafting in order to be of use (560 Levels just for DoH'S after SB release), the perk of an omnicrafter is been available craft anything but should not be better to an individual craft. In fact, if our system were deeper each profession should have their unique crafting process with a lot of little things to learn if you wanted to be a master of everything. Anything else should stay the same, it's very enjoyable and satisfactory.
Note: it's a giving that anyone depends on gathers.