I think the idea is that, since RH hasn't been acquired or gone public, they haven't yet "ended up" with a high valuation. It could all go away before the investors can get liquid (e.g., Theranos for a pathological example).
What if every company checked that box and couldn't provide lasting value beyond that? Do we still consider this a success because we're posting on a forum run by a VC?
That would mean an overheated late-stage market. (Which recent IPO data haven’t yet made obvious is a thing.)
I'm going to call BS on that one.
How long do you think that would be a sustainable situation? A high mid to late-private stage valuation is only supported by the promise of subsequent valuations.
If every company stopped achieving those subsequent valuations, it would feed back into the private valuations.