I'd agree with the gimmick part, at least where super glossy RT reflections are concerned, however the performance part is a rocky issue to talk around - people have always been willing to shelve some performance for better IQ, depending on the context.It makes sense when it really makes games better from performance and IQ point of view. Otherwise it is complete gimmick, for the stupid.
Obviously in a fast paced game, you want absolute performance above all, but with a slow paced game - ie Quantic Dreams fare - you want to appreciate the visuals as much as possible.
Ideally RT would have been introduced when we can have both, I'm a bit perplexed why nVidia jumped the gun - maybe they know something we don't about AMD's plans, because RTX pricing hasn't done them any favors to those I know that buy nVidia as a rule.