Yes I think thats fair and some great points made. On the first we do tend to put lads in earlier. To me though it's not like the lads are awful. Davies was very comfortable when he first broke through. There is a suspicion he was riding on the crest of a wave. But Vaughan looked good. Barkley was the best player on the pitch at both 17 and 19 when he played. Rodwell looked comfortable at 16/17. To me they are all a fair bit ahead of younger players you see at other clubs at the same age. I'd also ask, why is the exposure they are given not helping them more? And if it starts to become a lot of players, not just the odd one, is there something systemic in players stalling?
I do agree we have a Rooney affect at the club. Generally Evertonian's expect the best and can be quite unforgiving and impatient. It's a good virtue to have in general though I'm not sure it helps younger players much (or anyone who has a potential that's greater than their current ability). There is a lot of black and white thinking, in that you are either the best player in the world or terrible. You see it with Davies now. He's not brilliant so he must be terrible. I saw people saying he was below average for his age last season (as a 19 year old) yet couldn't provide any examples of players who were just average in the league.
There does need to be a re-appraisal. Not every player through the system is going to be a Rooney. I saw Winks on Sunday who is a very tidy player. He'd probably be slaughtered here, but for Spurs he does a very decent job. They will likely sell him for 10+ million. Good business if you can get it.
The bolded bit is an important point I think, and goes some way to explaining the reasons for fans becoming disappointed when players don't kick on.
You're absolutely right that Rodwell looked comfortable as a young player, and because of that we tend to project on players like him, thinking that being comfortable at 17 means you'll be above average at 20, and starring at 22. It doesn't though. I think sometimes people overestimate the step up in quality to PL football in terms of just being able to hold your own. People talk about someone being 'a Premier League player' but what does that really mean? Look at Bournemouth and Brighton, with loads of players who spent half their careers outside the PL now performing just fine at this level, or sides like Sunderland who have players who were once seen as PL quality struggling to get promoted from League One.
If we put someone like Browning, Williams, or Markelo (I'm just plucking these at random, before someone points out why it wouldn't apply to one of them) in the side now, they wouldn't look horribly out of place, but ultimately it may become clear that they don't have sufficient quality to stay there, because their limitations manifest themselves over time. I think this is what's happened with Davies, it's not that he's got worse, just that the more you see of him the more you see what he can't do.
This isn't just an Everton issue, the lower leagues are littered with players who had their moment in the sun as youngsters. Our lovable neighbours had players like Spearing and Wisdom who were regulars before dropping out of top flight football, and I remember United often using players like Blackett, Borthwick-Jackson and a couple of others 3 or 4 years ago, who have now slid down the leagues. Anyone remember when Macheda was the name on everyone's lips? These players haven't really stalled I don't think, they were used to plug squad gaps because they were capable enough, but they don't have a high enough ceiling to become fixtures in the side.
I think it's also worth pointing out that just being exposed to top level football doesn't in itself improve you as a player. If you have the ability to start with, then you can improve by getting used to the speed and strength of better players, and learning from the best. If you're not good enough though, it doesn't matter how many games you play, you'll never get there. That's why clubs cull 90% of their youth intakes, because they know that they can't just make anyone a top player simply by playing them.