Sure, if you hate virtual memory protections. Why don't all of those Android binder-using apps just run in one big process?
That’s the argument in The Birth and Death of YavaScript.
Which predates specter by three years
It was rather towards one-process-per-client such as PostgreSQL server or Apache HTTPd (long obsolete, fortunately). Hopefully PostgreSQL will switch to worker threads soon, and as for Apache HTTPd, I don't care.