“because priests do not talk about sin on the alter in homilies”
I’m confused. ALTER is a VERB. It means “to change.” In case you were groping for the word ALTAR, (a noun) i.e. where the sacrifice of the Mass is offered, you are not making sense either, as the priest would hardly be standing on it, as that would be objectionable to put himself standing on it.
If you were grasping for the word SANCTUARY, then I would agree. They do not address it enough, in a way that makes people admit there is such a thing as sin and they need to examine their lives and go to confession.