Their music was only a vector, or one of a competing range of elements of their existence, in a bid to make lots of money.
Besides the fact that being at least somewhat monetarily successful at what you do is the whole friggin' point of trying to make a living (unless you're a trust fund baby it kind of has to be), that's completely untrue; which is probably why you're getting the pushback.
Gene's background and total comfort in coming across in all the hideously un-PC ways his background is described is the only thing that can be linked to your statement. Every single one of these guys had the EXACT same trajectory as most of us in high school and afterward. They all got a guitar or drums, had garage bands, and then moved on to gigging bands and were eventually in bands that got record company attention. They were gigging musicians for years before KISS was even formed. Gene had other "real" jobs too because that's how he was raised, but the other three were typical of any other wanna-be rock star of the time with dead end jobs that really only supported their music habits, which took 100% of their passion.
Wicked Lester were signed (and both Gene and Paul not only did session work but had writing credits as well). Chelsea (sp?) (Peter's pre-KISS band) were signed. Both recorded full albums paid for by a record company. Whether they sucked or not only makes them like the thousands of other bands that got signed and never went anywhere. At least one of Ace's earlier bands was signed and I've heard the singles they recorded in the late 60s or very early 70s.
When they formed KISS they were no different than the Dolls and others in the NYC glam music scene, except two of them were far more disciplined. As for image, they just wanted to stand out. With the help of early band management and supporters they developed something different, and yes, they wanted fame and fortune. Just like every single other "rock star" that ever existed. The make-up, the costumes, the stage moves, were all inspired by contemporary music and show business culture. Enough of those involved have written books now that anyone who cares to know can find out where it all came from other than the four guys.
Music wasn't the vector, it was the thing. Gene and Paul were Beatle fans just like Ozzy was, and Alice was, and Don Henley was, and Don McLean was. They saw the Ed Sullivan shows and heard the albums and wanted to do that too. Same story as 90% of every other band that came up in the late 60's until the late 70s or so. You can think they suck. You can dislike their shows and merch, but does that mean the Beatles (who you mentioned) were only in it for the money? Was their music just a vector?
Gene and Paul may only be a nostalgia band now (where your critique has some merit), but the band that sold a million copies of Alive in 1975 was anything but. They were hungry and working their asses off to live the dream. And it's
that band that everyone here (defending them) is referring to.