Indeed, they can't. They are, however, posted by people who might have particular biases. First hand experience is always best.
Expectations also vary. Some people (I guess yourself) are accepting of it being a bit rough and ready. I was in ScotRail days as the price and promotion was appropriate to that - basically a youth hostel on wheels - and that's how the likes of OeBB NightJet are pitched too. But if you pitch yourself as a premium experience, I expect, and have the right to expect, as a bare minimum the quality of experience you get in a 4* business hotel such as a Marriott or "classic" Hilton or Holiday Inn (not Doubletree or Express) - for all I like Premier Inn, you'd need to shave a fair whack off the prices for that to be the comparison. And that is
sorely lacking.
I would be expecting pretty decent compensation for no food being served on the premises at that sort of hotel, for example, and to be notified as far in advance as possible, not just on arrival.
Or just be reasonable, knock maybe 40% off the prices and pitch it as a Premier Inn on rails, more like the Night Riviera, and everybody (bar the bean-counters) will be happy.