I always find it so careless when people say things like "let it go" or "this is progression". This being progression is obviously subjective and I personally really prefer these guys with vocals. Dreamhouse was killer and actually set them even farther apart from what a lot of bands sound like in this scene. I would have loved to hear then continue that. This is similar to what Oceana did, they changed their sound completely but stayed under their monkier for about a year with the same name. That wasn't progression, that's called a new band, just like this.
I'm fairly certain that the thought didn't inspire the reaction - it was the delivery.
People are certainly entitled to prefer Tides with vocals. Me? I love both.