Casuals won't even know what the 'free multi classing' even means.
I'm not sure that's how it works. You're correct that "free multiclassing" means nothing to them as a phrase, but it does mean something as a play experience.
Free multiclassing: "this game is so fun! There are all kinds of neat, crazy things I can try!"
Correct multiclassing: "this game is really complicated, how am I supposed to understand what I can and can't do?"
Those of us that always know where our PHB is, and where it is is usually close at hand, we're not the primary target market here. They're trying to get people who aren't usually into RPGs to try this.
I might hate the rule change, and I know a lot of people will disagree with this, but I think these stupid rule changes are good for gaming in general. The more that RPGs are mainstream, the better. At least in my opinion.
I hate these rule changes, but I think they're still good. The game is less about crafting the perfect build in the traditional way; it's clearly meant to be more about story than about combat.
