Becase different groups are always going to have different strengths and weaknesses. Asians are good at math but don't seem to drive very well.
This was the offending statement that was brought up.
Teens in Japan, Korea, parts of China, etc. do better on standardized math tests than U.S. teens, who rank in the bottom half of the world. That is the factual statement.
"Asians do better in math" directly following "because different groups are always going to have different strengths and weaknesses" in response to a post about race does not read like the above. It reads like a racial stereotype. It's obvious to see why people would take it as such.