When the glofish were first introduced, I didn't think much of them. Manufacturing fish that glow felt bizarre, and given the variety of lovely natural fish, why spend that kind of money?
But the 5 yo loves them. So we bought some, 2 summers ago. They spent the 1st summer in a tub out back. No filter. Random water changes. Floating plants, fed when the kids asked if they could feed them. And the fish thrived. Brought them in for the winter, and they've been inside ever since, with plans under way to move them to the youngests bedroom. Those are her fish. She loves them. She gets to feed them, she looks for friends for them, she wants to know more about fish and more about aquariums and more about science (although she doesn't know that's what she's learning) as a result.
The glofish are healthy, active swimmers. Any tank with them is going to pop. Are they 'natural looking'? No. But then, neither is a tank with altum angels and albino cories. Or hillstream loaches and apistogrammas. As much as people strive to say they create a 'natural' tank, at the end of the day it's a glass box with animals and plants and objects that may or more likely do not encounter each other in the wild. If you don't think it's attractive, don't buy them. So long as the fish are healthy and able to behave normally, I don't see the problem. Breeding fish to be heart shaped or tattooing them is a far uglier practice than making them 'glow'.