I see nothing wrong in hybridization and gene injection, but I just don't like Glofish. To be honest, I believe, they are a ploy to get people into the hobby who shouldn't really be into the hobby. I can assure you the vast majority of Glofish's customers are children, and few children, especially those that are attracted to the hobby by the color of Glofish and nothing else, are capable of maintaining a fish tank without any decline in interest over time. For these children, their Glofish become a burden--and when fish become burdens, they are often abused.
Of course, there are people, for example Eupterus, who keep Glofish, despite their, in my opinion, freakishly inorganic looks, and do not abuse them. But I doubt these people are common.