In the beginning was ProTools and Bomb Factory with all the best GUI, all the old gear on your screen. And that has been a big plus for PT, (c'mon everybody wants a 1176 on the screen!). And everybody saw "old gear on the screen" was good.

Then UAD came to give the possibility to have the old gear without ProTools (and to have a similar system, you know to free your cpu from the burden).

Today Waves gives us the digitalized old gear without even bother with the PCIe card

And for the DSP, well, today machines are already so powerful, and they get more and more really fast, I don't think anybody (or I hope so) buy DSP for the power, but for the quality of the plugins..