Why people still miss her:
One of my favorite parts in the Selena movie is when she performed somewhere and they only make a certain amount of money. Her dad tries to talk to the guy who pays them and says "What can I say? She's just a woman".
I don't know if that scene really happened or not, but it's still representative of the attitude at the time of how hard it was for a woman to try to break into Tejano music.
I also feel like a lot of Mexican Americans relate to her because a lot of us did not grow up speaking Spanish. Selena grew up speaking English and mostly spoke Spanish when performing her songs. I grew up in a somewhat bilingual household but I was not raised to speak Spanish.
It's hard to grow up trying to fit into two cultures. This scene from the movie explains it best:
I leave you with one of my favorite songs she performed at the Houston Astrodome (which held the record for the biggest attendance until 2001)