@Stuart

Perhaps I wasn't clear enough with the dictionary definition: "lame" does not only refer to people with injuries. It refers to animals, objects, concepts, etc. and has carried that set of definitions for quite some time.

Is it offensive to a horse to describe it as lame? Or to the excuse shown in the dictionary's example? This is NOT a term that specifically targets people with disabilities; on the contrary, people with such injuries (should they be referred to in this manner at all, which I personally would not do) are only one of several different possibilities to which this word may be referring.

And, as I said, this is not true for the word "gay." When used in this context it is referring solely to its newly-acquired slang use, which takes something that the person using it doesn't like and labels it as "something a gay person would do or like." This clearly IS intended to put down people of a specific group.

Also, I would be very surprised if this EVER becomes a universally acceptable phrase. If, for example, you feel that you have been cheated and said, "Man, I got jewed!" you would obviously be uttering an incredibly offensive statement to members of the Jewish community. The false stereotype regarding Jewish people and their attachment to money has been around for hundreds, if not thousands, of years. And this is, thankfully, not a socially acceptable phrase either.