Why do fans care about the off-screen relationships between Trek actors? Picard and Data were close, but why should anyone care whether Patrick Stewart likes Brent Spiner or not? What difference does it make?
This. Never understood why people cared what actors did or who they got along with behind-the-scenes. They sure don't give a shit about those watching the show.
Also, it probably didn't hurt that, after a rocky start, TNG was a huge hit, whereas the subsequent shows had to live in its shadow.
TNG was a huge hit right from the beginning, getting renewed for a second season in early November of 87 six weeks after the show premiered in most markets.