Stanford tennis is kind of like Notre Dame football. So good, for so long, but the game has moved on, the game is deeper, there are many more top players available (many of whom don't want to or simply cannot, for academic reasons, attend Stanford), there are many more great programs.
Yes, Stanford still remains a blue blood program, an elite program, with great tradition and a lot of resournes. I assume they will eventually win more NCAA titles. But, the days of winning as much as they used to have passed. The landscape is much different.