Your points are fair, not going to argue with you. I think you got me wrong, or I didn't express myself correctly.
First of all, I didn't say those we're the reasons he's been playing "worse" this season, cause honestly I don't see why people say so, except for his bad crosses.
1. Again, not saying this is the reason, but it might be playing a factor in motivation (not only for Montoya, but other La Masia players as well) if the first team coach doesn't trust young players (I experienced it first hand), you can't expect them to give it their all for so long and still not getting their chances.
However he's played a lot this year, and I think he's shown, along with Bartra, that he's one of the best defenders Barca will have. Whether you'd want to admit that is another matter.
2. A fullback is a fullback, and his first priority is to defend, which Montoya does really well (deny however you want), and I bet you if you play him in CB everyone will be amazed (I hope Tata tries it out in friendlies - Puyol was a RB when he was younger, and they tend to do well when converted to CB). Going forward is also not one of Montoya's weaknesses (cause every La Masia defender should be able to do so) and he's assisted a number of goals this year because of that. I do however believe he should be working on his crosses, but that's just training.
There is a sense of "Barca fullbacks must always go forward" nowadays, but that's exactly the reason why the defense has been suffering. I'd say play Alves and Adriano (who's defending sometimes can be suspicious like one of the goals scored by Real Sociedad Saturday) or Montoya and Alba, and let one go forward and the other remain at defense (I think it's clear that Barca, under Pep, mostly played 3-4-3, with a fullback acting as a CB and the other going forward, nowadays it's more of a 2-5-3 at times, and that leaves the defense open).
3. Yes, chances given, but if he plays well let him continue, which was not the case. And I agree you have to earn your position, but frankly even Bartra earned it over the likes of Pique and Mascherano, but even then he wasn't playing as much as he "deserved" to. Alves played badly for some time this year (again, you'll probably deny this to forward your case), and he still got to play or worse, Adriano (who is a far worse defender - not offensive help - than Montoya) played in RB, while he's mainly the LB cover.
I remember a match when Tata was shouting because of Montoya's cross, but he was playing really sound defensively. Why not tell him to stay back and let the other fullback go forward or let him go through the middle. I bet you if Montoya and Alba play together, which doesn't happen enough, Barca'd be good on defense and offense.
Finally, playing regulars in and out, even if they under-perform in several matches (that's been the case for most defenders, and more so for Pique), leads to complacency (you say they should earn it, but that goes for the regulars as well). It also leads to injuries and ultimately to the downfall of the team. Again, Pique is a very good example. Pique was playing very bad last year and people wanted him out. I said then, that he just needs competition and rest, and some on here laughed at the idea. Come this year and Bartra performs well and guess what? Pique does well too! Coincidence? I'd say no. Let there be a fair competition between them and keep everything fresh. Martino's rotations were really good at the end of last year, but for some reason, it's been lacking lately, while defensive rotation has not been good to begin with.
When you don't trust young players, you create a gap between the older and younger players and that turns against you the next few years. You tend to forget that the players (from the least to the greatest) is what makes the club, whether you're Barcelona or a third devision team. No need to be all "this is Barcelona, we deserve better youth" cause then there's no evolution. Players can only play so much years before ageing, look at Puyol, who everyone wishes could play forever. And even the established players started out shaky (even Xavi and Iniesta, who people didn't really notice until they were older). Barcelona is the best because they teach and motivate really talented players to be the best, not because they are already the best when they start out. That's why I like Puyol's attitude, cause at least he's willing to teach Bartra some things, and that's why Pep, who had the guts to trust young players and punish complacent ones is the best coach Barcelona has ever had. And that's why Eusebio should be replaced as fast as possible.
Sorry for the long post. You most likely won't agree with me on most points (if not all), but that's just my 2 cents.
