Once, waaay back when, ('79 I think) rolled 5 18's and a 17 in front of the DM. He said he'd let me play it ONLY if the character classes and race worked with the stats. (Note: original AD&D here) Since we had two other players working toward bard at the time, he said that wasn't an option, so went with a half-elf fighter/mage/cleric. The DM said yes after rolling a 99 on his STR. Said it ment that the character is a MUST.
That character (now epic level) is still around.
I have been playing since college (late 70's) and DMing for the last 25 years or so. I have no problem with disallowing a character that could affect game balance, or having one of mine tossed for the same reason.
That said, I hate point-buy systems. (Way too Lawful for my taste.)