New at this....why run video through processor?

Why run video sources through the processor? Is it just for convenient source switching through one remote? I would think it is better to go from DVD player or HD cable box directly to the monitor. Especially when source and monitor have HDMI or DVI and processor does not. The reason for the question is that I am currently upgrading the processor and have noticed the lack of HDMI on any of them. I do not know if it is worth spending big $$$$ on a processor that could be obsolete when newer models come out. Just in case it matters, my monitor is Toshiba 65" HD with component and HDMI inputs. Not DLP or is the big heavy one....CRT I think it is called. Thanks for your help.
Some processors do video upsampling of all components to 480p or higher. In many cases the upsampling is better than the outs of a DVD player with DVI or HDMI.
I also run all my video directly to the TV, currently I use an external DVI switcher (the Gefen one FWIW) and it works very well.