What's with all the spin-offs?

This year, we're losing Breaking Bad, Dexter and HIMYM.

Yet, we're talking spin-offs already for all three shows. And a spin-off for Walking Dead, too. Really?

The BB spin-off Better Call Saul is already in the works and the others are just rumors, but I hope they don't happen. I understand it is hard to let go of these characters, stories and places... I understand that some spin-offs are awesome (Frasier?) but I feel like it is just cheapening good - no, GREAT - television. These shows will go down in history as some of the best (or in Dexter's case, the first few seasons will...) and I don't want their legacies muddled because of some silly spin-offs.

Plus, for every Frasier, there's a Joey.