I think part of the problem is what
@Lanolin is talking about (I think) and that is that there is a difference between reacting to a particular game (or incidents in the game) and reaching a judgement about the player overall.
If I say I didn't think Episode 6 of Westworld Season 1 was that good, it doesn't mean that I think the whole series is rubbish or that I refuse to watch it any more or that there weren't interesting developments in it.
Likewise, if I see and say (as I did recently) that I thought Davies seemed slow to react loose balls or unexpected passes in a particular game doesn't mean that I think he is crap and shouldn't be in the team and isn't able to progress.
But then you get the responses "great fans, having a go at the next young player and driving them out of the club".
(I appreciate it might be equally infuriating for those who are more enthusiastic about Davies and his performances to see the posts about him never being able to develop, but that is not the opinion of everyone who might be critical of his standards in a particular game.)
The other part of the problem with any young player is that we don't live in a dream world where we are winning every game 3-0 at half time and can give youngsters a runout in the first team with no fear. So you do get the problem, as we have seen with DCL and Davies and, to a lesser extent, Kenny, Holgate and Lookman, where they are thrust into difficult situations and the team and fans are relying on them as they are every other more experienced player to win important points.