Enterprise was a good show, some people like it some not, still the question is why DS9 is behind 400 other shows.
No TV show is supposed to be a purely intellectual product, books are for that. I don’t think that violence was used extensively in DS9, it depicts a war after all. DS9 is too untypical for the average Trek fan – they expected a 5-year mission and parables but received a war and a dubious message. It changed the ST format too much and it deconstructed the ST mythos, this is hardly a way to attract the hardcore fandom. At the same time, DS9 is part of the ST franchise, which puts off the non-Trek audience. So DS9 falls into the no-man’s-land.
At some point, the audience became oversaturated with ST, several series were running concurrently or in a rapid succession. In the meantime, the show-biz introduced new approaches and topics, new generations came, they grew up with other shows. ST remained frozen in its timelessness and unwillingness to change and face the reality.
Contemporary TV viewers are segmented into small specialized audiences (narrowcasting), each audience votes for its show, so recent shows appear higher on the list. Enterprise was aired last so the collective memory about this show is fresher.
DS9 will drop even further, not because it is a bad show but because there is always something new, film industry is an ongoing process.