Turing wasn't trying there to articulate a single target for AI research, he was responding to the claim that artificial minds were not possible even in principle. His response was basically, try this, if in open-ended conversation you couldn't tell one from a human, would you really still say there's no mind there? As you say, that's a really high bar from where we are, then or now.

I'm sure Turing's own goals for AI were broader than eventually passing the Turing test. He worked on neural nets himself and would've considered progress in perception as partial progress in AI.