It's not emulating the party support aspect in normal parties which is a persistent identity of blu mage, despite having a collection aspect, it was still a party job that could run with other jobs as a support, it has about the same collection factor as summoner has in some games. Also your value point is purely subjective, for many it has far less value than normal jobs and even crafters/gathers. As to what it would look like as a full job? Well we can already see that with DPS mimicry's dps rotation which it is doing 90% of any raid, a quirky rotation that could have some party support mixed in, if they would implement it as a new soul crystal it could be Blue Battlemage (like how red mage in ff12 is called red battlemage), but there should be no reason why the limited portion and full game portion of blu couldnt coexist as a menu option