Why can't youth change meanings?

I had an interesting conversation a few days ago with a colleague of mine. It was about words. In general, all words are created equal. However, society takes words and assigns meaning to them that suits its needs. It is well known that any or all words could change in a generation's time. So, as I was talking to my friend, the idea that the current young generation (16-26) is "the harshest-talking generation" came up. The word "bitch" was used as an example. It was said that young people use bitch as easily as they drink water. They don't think twice about it. Then I said that that was probably good because that means that the stigma that society had assigned to the word had been overcome. There's some truth to that. I know because familiar words begin to also show up in variant forms. I hear "biatch" about as often as I do "bitch." I also know that the word has broadened its meaning. Men could never have been referred to as bitches. Now men refer to each other as bitches.

It's hard for the older generation to accept changing mores from the younger generation. But on this matter, I think change is good. Why would an old fogie want to go to the grave always assigning taboo meanings to words when they were all created equal in the first place? That is just sheer stubbornness. Why not allow something to change from evil to good for a change, and an overdue, welcome change at that?