Part of it was a lack of shows… at the time there was very little science fiction. Today, there is too much to choose from.
Not to knock B5. It was a good show although it lasted a wee bit longer than it should have—after year three, it felt…well, judge for yourself.
Or not. TBH no one is forcing you to watch it. You don’t have to like it. It’s fine to like something or not like it.
No judgment.