Could we not? There are enough of the damned bloated things floating about. Could we just forget they exist and stop assuming clients want to navigate slow, resource-intensive pages for everything?
Dynamic content fetching makes sense in many cases, but making everything a dynamic fetch is rarely a good idea.
For example, if I want to check a company's contacts page, I can generally visit www.example.com/contacts and get a simple page with their contact information. If they've chosen a SPA, I first have to load a shitload of unnecessary javascript and probably wait for all the animation effects the marketing department forced on the developers before I can get to the information I want.
Not to mention most implementations are absolutely piss poor at handling repeated clicks. Ever since Youtube decided to jump on the bandwagon it's been an absolute pain to use, with videos continuing to play audio even after you've changed videos. And that's Youtube.
If a team with near-infinite resources can't do it right, I have very little faith in anyone who considers SPAs to be useful. As far as UX goes, they are abhorrent. They tend to consume way more client resources than they should ever need, causing browsers to slow down to a crawl even while they're in the background.
If you ask me, the sooner this fad passes, the sooner I can get back to ranting about those kids on my lawn.