Same. I actually hate that some of new groups just do it for the sake of doing it. I personally think a unit should be made when they can offer something new and fresh from the original group's material. Something like Orange Caramel or TTS.
But honestly what was the point of Pristin V and Ogugu? I'm not denying their quality, they both released good material but they weren't very well thoughtout units if you ask me. It seemed like they had a song on their hand and just put a few of the girls together to do it.
Orange Caramel is amazing, but I guess it's not the norm.
Sub-units seem like a quick cash-in for companies, or just to keep some profitable members in the spotlight. I think in the case of Pristin and Gugudan, either they were having big drama in their ranks (the former) or some key members weren't available (the latter).
I assumed Pristin V was a group of the older members (and I could be wrong) who did a more mature pair of songs with a smaller choreo set. Their Spotlight video was gorgeous, and almost exactly how Red Velvet does Automatic in concert. Which I love... I think Pristin V works really well as a unit actually, and I hope they continue.
When you have a huge group with a broad range of ages and personalities, subunits can be an excellent way to capitalize on some of the artistic ideas that may be out of a group's concept. This may be sacrilege, but I like OEC almost better than the entire LOONA assemble - even though I love all the members individually, especially yves and Heejin. I would love to see more from yyxy, too. With Yeojin, though. C'mon, BBC.
Full disclosure though, speaking as an fan of OC, OEC, f(Amber+Luna), and I actually love Twinkle.