I used to think the same way, but trying out a non-SPA site really feels jarring now. The intermittent blank screen and the 2 second wait period makes for a shit user experience. I'm much more used to the fluid desktop-grade UI.
My only gripe with SPA was the initial load-time (looking at you Gmail), but with virtual-dom, being able to generate the html on the server gives you the best of both worlds.
You don't have to go SPA to avoid the page reload. AJAX works just fine with regular webpages as well, judiciously applied on the most latency-sensitive actions.
BTW, you're posting this on Hacker News, which is the ultimate in retro Web-1.0 technology. Heck, it even uses tables for layout.
SPAs use Ajax to sync data with the server, but the templates/assets are on the client already. In a regular webpage, Ajax would have to pull the templates for the new components as well.
I think this is what Gmail does, though it still takes forever for the initial load. Anyway, I can see this becoming a complicated mess very quickly, and find Ractive/React to be much simpler solutions.
As for HN, I doubt anyone comes to HN for the design. PG and YC's brand helped create a solid community with good content and good discussions, which is what keeps bringing us back. But let's call a spade a spade - the UI design here is a joke, even more so considering that its target demographic is the tech community.
My only gripe with SPA was the initial load-time (looking at you Gmail), but with virtual-dom, being able to generate the html on the server gives you the best of both worlds.