I think there's a bit of that,It's a 4/5 on the PS Store right now and I can imagine a lot of those were pre-orders and what I will say is more people are likely to complain about something than rave about it...so all-in-all it's doing ok...however maybe PC gamers are harder to please (@50%) but then it did have a lot of technical issues on PC.
What I will say is that watching the (edited) videos a lot has changed in the last few months (as in taken out) - who is to blame? We may never know, I think the game was hugely ambitious and Hello Games (small studio) were under great pressure to get it out...I think if it'd been cheaper there would have been more leway it does seem like there will be more stuff added that potential was supposed to be in the full game. Personally I think they should have gone for the Elite thing of 'core game @ £30 then £10 for for each add-on - or something like that.
If anything the game was upgraded at the last minute (day one patch), not downgraded. If the game had released without the day one patch, it would have been a bloodbath. I seriously question how many of the features and ideas that were hyped were even remotely in a workable state.