And there would definitely be a market for it, just like there's a market for spicy food or BDSM. Indeed those aren't apt comparisons -- an AI that's not a sycophant might be more comparable to food with a little salt?
Making it always talk back would not be an issue, just like making it a complete sycophant would also be easy. Any form on nuance would be hard. E.g. if i'm complaining about my job it should talk back if i'm being unreasonable. But also take into current state of mind, etc. Maybe using thought chaining you could get something like this to work but from my experience, i doubt it would be very good.