While I agree that the back button _should_ work in an SPA, it's common for it not to. And it's common for other functionality to break. It's not hard to fix that and, for a well engineered SPA, such things typically do work. However, it _is_ extra work and it _does_ get missed. As such, SPAs tend to have more issues than non-SPAs. As such, as a user, I tend to prefer non-SPA implementations unless there is a strong reason that the SPA makes more sense.