You are not giving reasons against SPAs which is what you said earlier, you are giving reasons for using the right tool for the job. Which nobody disagreed with from the beginning, not me anyway.
I think being inefficient ('writing a text editor in sed') and impeding doing things the right way ('it's a lot easier to take a clean REST API and use it from JavaScript than it is to take a purpose-built SPA and try to turn it into a proper REST system') are reasons not to write SPAs, no?
And the presence of reasons to write proper HTML/HTTP apps implies why one shouldn't write improper SPAs, no?
I think being inefficient ('writing a text editor in sed') and impeding doing things the right way ('it's a lot easier to take a clean REST API and use it from JavaScript than it is to take a purpose-built SPA and try to turn it into a proper REST system') are reasons not to write SPAs, no?
And the presence of reasons to write proper HTML/HTTP apps implies why one shouldn't write improper SPAs, no?