As the resident Kiss fan here, I have to say I completely understand your opinion. They did a lot of damage to the credibility of the music with their marketing of toys etc.
That said, the early early stuff is very progressive and riff driven. They were hungry and wrote some great rock songs. Then, when commercial success started to occur, we have the Kiss that you describe.
If you listen to these songs with earbuds on and without the preconceived notion of four adults in clown makeup, maybe you'll change your mind.