No it's not. A join means you have to wastefully repeat the same parent fields for every row. That's wasted cycles serializing and deserializing and it's more work on the client.

It's absolutely ridiculous to make a blanket statement about this very useful feature.

I've done the benchmarking on many applications of this tactic. It very often works better with multiple select statements. I'll certainly trust hard performance numbers against an ill conceived opinion any day.