Actually, what it shows in this case is that you're relying on the good will, stupidity, or telepathy of the players to realize the kind of characters you want or don't want.
If you adopt an unweighted point buy and someone comes back with a combat min/maxed character like that, what are you going to do? Curse them out and call them a stupid munchkin then show them the door and tell them not to let it hit them on the way out? Of course, by adopting the system you were the one who told them they could do it in the first place so maybe that's not really fair.
And if that's what you're going to do, when do you decide to go on your anti-munchkin rampage? Even if you ask them up front not to create any "munchkin combat monsters", that term really needs definition. Is anyone with a prime stat of 18 a munchkin? Anyone with two 18s? How about all these characters?
A paladin with str 18, dex 10, con 14, int 8, wis 12, cha 18
A wizard with str 10, dex 16, con 16, int 18, wis 10, cha 10
A fighter with Str 18, dex 12, con 16, int 14, wis 8, cha 12
A fighter with str 18, dex 10, con 14, int 8, wis 12, cha 18
And then for the follow up question? Does the last player become a munchkin if he multiclasses to Paladin or Holy Liberator after getting weapon specialization?
How min/maxed is a player allowed to be before you get upset with him? The unweighted system doesn't answer any of these questions.
The weighted point buy system at least ensures that you won't see 18 18 18 10 8 8 unless you're allowing a really high point buy that would lead you to expect those kind of stats.
Shard O'Glase said:
It's not, but someone will tell you that oh no you could get an 18,18,18, 10,8,8. Yeah something like that could suck, but all that shows is that min/maxers can break any system.