People, especially the Japanese players, wanted a sequel that continued the story of Harry Mason. That's why Konami forced Team Silent to change Silent Hill 3 in order to incorporate all the elements to force a connection to Silent Hill 1. Silent Hill 2 had so many complaints about not being connected to Silent Hill 1 that it permanently disfigured Silent Hill 3.

I guess back then we didn't fully understand the concept of a sequel with a 2 in the title not directly continuing the story from the original. Whatever the case, the fact remains that Silent Hill 1 was immensely more popular than Silent Hill 2 for a good long while. It wasn't until recently (maybe within the last 10 years or so) that Silent Hill 2 came into the spotlight.