That's among the stupidest things that I have ever heard.
Which I guess is to note that the fact that the rules say it, doesn't mean it is a good idea to be accepted blindly.
This was good old 2e; rules were all over the place and that was the OFFICIAL stats, courtesy of the Complete Book of Humanoids (and later reprinted in Skills & Powers). Let me give you a few gems from that era...
Aarakroca, to balance their flight, are claustrophobic and suffer a -3 to attack rolls when in an enclosed (building or dungeon) area.
Bugbears, Centaurs, Firbolg, Gnolls, Minotaurs, Ogres and Half-ogres all take damage as large creatures. This meant that some weapons (longswords) did more damage, but others (daggers) did less.
Bullywugs must wet themselves THREE times per day (a waterskin's worth) or lose 2 Con points, cumulative per day missed. 0 = death.
Centaurs (and I quote) " They have difficulty negotiating underground settings." Nothing else said. They are large, as previously mentioned above.
Firbolg, in addition to being large, cannot wear armor/shields, need double XP to gain a level, half 15% magic resistance that can't be turned off for beneficial spells, and don't apply Str bonus when using human-sized weapons. (For what its' worth, they were huge creatures that could use giant weapons [x3 damage] and had lots of spell like abilities)
Goblins, Kobolds, and Orcs, have -1 to attack rolls in bright light
Hobgoblins get off easy, dwarves and gnomes get a +1 to hit them (thanks to those races racial traits) which isn't inherent to the race but the enemy race's traits.
Lizard men, like bullywugs, must wet themselves (only 1 day) or loose 3 Con points. They also start with less proficiencies in weapons and must make Wisdom checks if food or treasure is nearby to keep focus. Yesh...
Half-orcs have no innate penalty. They just got shunted here after they were kicked out of the PHB. Everything you know about 1e half-orcs apply.
Satyrs are prone to distraction around females with Cha 15+ or alcohol, may require Wis checks to keep focus.
There were other races in there, but I cherry-picked some of the more common ones or those who made it to 5e in some form or format. I guess if a DM is looking for a balancing factor, feel free to bring back those 2e penalties to the exotic humanoid races. 2e versions of aasimar, tortle, genasi, tiefling etc exist (as does BECMI versions of triton and most of the above humanoids) if you are interested in ideas to further limit their playability for the sake of verisimilitude.