They just need to write the story to explain why we're an 'evil' job, but not 'evil'. Look at DRK (we kill like 15 Temple Knights, minutes after being told 'don't make a scene'), BLM (half of the cause of a calamity), WHM to an extent (since it's the other half of said calamity), now RPR where we don't just summon voidsent, but literally offer our physical form to them in some DBZ fusion thing. We can absolutely be an 'evil' or 'not-good' job, but the story always explains that 'no actually, we're using it for the good of the realm/people, and showing it can be used in a positive way'.

So, have the Necromancers we have seen and fought so far (eg the POTD guy) be the corrupt bad ones, who are trying to use Necromancy in a selfish way, to extend their own lives blah blah. Then, we are using the 'true' form of Necromancy, used to aid souls unable to pass on peacefully. It doesn't all have to be 'summon skeleton' and 'summon zombie', Necromancy covers a whole broad range of magic.

Plus, what's more thematically fitting for a Necromancer, than an LB3 that revives all allies