Traditions evolve. Or clubs become Liverpool.Youth is part of the traditions of the club, some supporters (like me) enjoy seeing youth team players come through more than signing big names. You shouldn't be that surprised by this considering the clubs history is built around the busby babes etc. It's not about blindly supporting any young player that gets a shot. For me it's that it is better to at least start with positive intent and support them rather than knock them from the off.
For what it's worth I disagree with you on Lingard, I think he is going to make it. The jury is still out for me on McNair but again I'd rather support the lad than knock him from the get go. As I said earlier to @devilish, I remember him knocking P Nev in much the same way he is knocking McNair. I think most would agree P Nev was a great servant during his time here and had a decent career in the end.
As I say, I just don't think the default position on youth should be 'they aren't good enough'. The nature of a young player is that they probably aren't good enough. But it's much more rewarding as a supporter to at least give youth a chance and SUPPORT them I think. Every team has to have its journeymen. There's nothing wrong with that.
Don't get me wrong, I would like to see us producing and then getting the benefit of young players as anyone else. But not to the hindrance of the team, which we have been doing recently.
We use Barca as example, but Barca doesn't waste time in donkeys as we do. They sent Gerard Deolofeu to Everton, despite that he is a better winger/attacking forward than anyone we have produced since Beckham. They give time only to the best of the best, and so at times produce top players. We give games to players who will probably won't make a career in EPL.