Actually there was support for the Communists in Afghanistan. A lot of the resistance were more opposed to the equal rights with women than the communism.
Let's say you're an Afghan peasant in 1981: what's going to piss you off more: that a few women in a city you've probably never visited are attending university and walking around without burkhas OR that the soviets just bombed your village and killed several of your relatives, and stepped in and made someone from a rival ethnic group that has never gotten along with yours the governor of your province.
Your typical muj probably did not know or care what Communism was. He probably didn't know or care about women's rights either. He fought the Soviets becuase they were on his land, interfering with his livelihood and his way of life.