How does this even make any sense? The only sense I can make of it is that the 4e books (?) somehow grant me a stick to say to my players:
"NO YOU WILL CONTINUE SHOWING UP TO GAME SESSIONS WHEN YOUR CHARACTERS ARE LEVEL 23 OR ITS STRAIGHT TO THE COME AND GET IT GULAG WITH YOU! YOU CANNOT GO TO THE MOVIES OR REMODEL YOUR KITCHEN!"
Whereas in prior editions, the books (?) only granted me the milquetoast authority to request:
"Hey guys...can we maybe keep playing this campaign now that you're level 23?"
I have yet to see this stick. Maybe you got a special Gestapo Collector's Edition that sold only a few copies to exclusive clientele (of which I am clearly not!).
I just love it when these lame ass answers come out because it shows you don't have an actual argument.
I would you to actually go and read the 3rd edition books, followed by the 4th edition ones. After 20 play is in a totally separate book that is, by default, optional. I mean if we actually want to use your ridiculous line of reasoning, then level 2 to 20 is purely optional. 4th edition, by default, has three tiers and it is assumed these tiers will all be reached. This ain't about GM fiat.