I just sort of assume to the casual audience the name Guilty Gear is poisoned. People are aware of it, know it's not their thing, and won't take a look at a new entry even with fancier graphics and more accessibility.
Whereas new fighters at least have a chance for new audiences.
Not saying GG is bad, it's probably my favorite 2d fighting series in existence, but out of everyone I know irl, no one will touch GG outside my one local friend that I used to play locally against since XX days. It's either too hardcore or too anime for everyone else. Like I said, fighters in general are niche outside like Mortal Kombat/SF, so being a smaller niche within a niche is just gonna be hard to ever get the breakout sales.
I guess we'll see if rebooting it and making it more accessible does anything for them. Will also be the first fighter for PS5 I think?