In 1999? It was the Hallmark of munchkin players who didn't care about racial identity and only wanted to play the most powerful or wacky combos imaginable. Specifically, ruined the story that dwarves hated magic and were so antimagical they couldn't do it (possible exceptions for clerics, depending on edition) and paladin was a human only concept and the ability to be one a human racial trait. (No joke, that was argued). The concept of any race being any class was so reviled that the 3.0 DMG added a half-ass "option" for the DM to limit them placed in the optional rules section.
I've come to believe that, except for the most hardcore grognards who still use 1e initiative RAW, most people and game publishers allow any race/class combo. But that was a huge area of disagreement when it was announced.