I like the glycerin in the few soaps I've had that used it. I'm not sure what it's for. Maybe it's for extra moisture. At any rate, I don't object to it.
I always put glycerin in my soap when I make homemade soap, but I know that some people are completely against using it. I have never understood why people don't like it though.
I like glycerin especially this time of year. My hands get so dry and it's important to use every opportunity to add moisture to the skin and cuticles. The wrong soap can undo every bit of moisturizing I've been trying to do.