I wanna play my goblin paladin and not suck and you. can't. stop. me. And papa WotC agrees.Again, thats what the attribute array is for.
Want to play a strong and clumsy elf? Dex is the dump stat and Str is the highest. Sure you will still be more dexterous than a clumsy human, but not as good as nearly any elf. To them you will be clumsy.
And you will overpower most elves, be equal to many humans but still struggle against strong orcs.
In the end it comes down to 2 things.
1. People somehow thinking that different fictional races being different is somehow racist (see @Faolyn's post). Which strangely only seems to be a problem in fantasy, not in scifi. I haven't heard any complains about Vulcans.
2. People refusing to play anything not minmaxed with an 18 in the primary attribute which imo is not something you should cater to. Thats not role playing. No one is preventing them from playing an elf barbarian or orc wizard except their inability to play something not minmaxed.