It's not odd considering that people probably don't have the patience to wade through so many episodes and Spike basically killed TNG with relentless airings and no let up.
At one point it, IIRC, it was three hours every day for a while. I don't care how hardcore you are, watching the same episodes every two months for six years has to be overkill.
As for myself, my heaviest viewing of Star Trek (in general) was during junior high and high school. Once I hit college it tapered off significantly and has stayed that way ever since. I go five years or more without watching the same episode twice.