Why so many purple Scrip sets for Dol/DoH?

[Coronal]

A different set for each one?

I understand more mainstream crafters would generally have crafted and melded gear but the blue Landsaint's was fine for gathering.

Now there are 3 sets, one for each gathering profession (full sets not just main hand).

And a different crafting set for each craft?

Seems a bit of slap in the face for casual players who just want to tinker around crafting.

[Hatfright]

It's like that with every expantion. The unified sets will be introduced in later patches.

[Jojoya]

As Hatfright said, it's been the same system since Stormblood. The first scrip set is always class specific for glamour purposes. Role specific sets are usually added in the x.3 patch.

The crafted HQ 560 sets are perfect for players who just want to tinker around with crafting.

HQ 560 (only slots also available in scrip, no materia added):
1932 Craftsmanship
2174 Control
202 CP

570 Scrip gear:
2016 Craftsmanship
2226 Control
202 CP

(The numbers don't include what you're getting from secondary tool and accessories since those aren't available from scrip at this time so I don't know what you plan to use)

As you can see, you're already at almost the same stats. You can add materia as you prefer to boost stats to be equivalent to or better than the scrip gear. Even if you don't want to add materia, the HQ560 is more than sufficient for all currently available recipes. You'd only need to add materia if you plan to "tinker" with Master recipes once those are available.