"High quality, world class text search is a basic prerequisite for a production web app these days"

That is a pretty bold statement, that I can't agree with. The right tool for the job can vary dependent on need. Perhaps you are building your MVP or you have a small ops team or search is an admin function or etc ...

If search is one of the main components of my site, then no, I'd probably not use Postgres for that. On the other hand, out right dismissing it sounds like a recipe for shaving yaks.