On the one hand, the GloFish process manipulates their genes, it doesn't add physical dyes like "painted" fish, so it's not inherently bad for the fish themselves. On the other hand... Oof.
I don't mind the fish themselves, I mind how the company markets them and pushes tiny tanks that are wildly overstocked. And now with their bettas they're also selling on their website a six-betta sorority, which grinds my gears because I don't recommend sororities in 99% of situations anymore, especially not to the kinds of beginners who are going to be drawn to wanting a tank of glowing bettas.
There's also no telling how well their bettas are bred, if they're genetically diverse, if there are any health problems in their lines or even just if they're well-formed enough to be "pretty"... Which of course any breeder can fumble (and many suppliers for pet stores are pretty awful), but this isn't a small company so they're going to be churning out thousands of bettas from whatever their foundation stock is.
I'm also curious if these bettas have been sterilized (and how), because otherwise I know people are going to start breeding them with regular bettas and that could have some very interesting consequences for the species.
Personally? I will not buy one. I can't say I won't for certain- heaven knows I've been suckered into a betta I didn't intend to buy before- but I don't plan to support this new venture of theirs, definitely not if this new strain of betta hasn't been handled with care. Maybe after a couple of years at market these glow bettas will prove to be exceptionally healthy & hardy and I will change my mind! But I'm not counting on it.