I don't think the general public is engaged enough to understand the difference between "license" and "buy". They will look at the button and think "This is what I click to get it" and don't understand that they are just temporarily renting the thing. To most people, "license" is a noun: something you carry in your pocket to drive. The word is already overused by media vendors to confuse people.

It does defuse any excuses like "why do you say I can't buy games? I bought this game just now" and that can be a stepping stone to actual change.

That's assuming there's an alternative.

Yes, the language should be clear and precise.

Also, if the whole industry string-replaces "lease" for "buy," I doubt the effect will be much.