Yes it's still early days for Garnacho and Mainoo but they are showing great promise and could potentially develop into "world class", Rashford is wildly incosistent but has shown glimpses of being more than capable, and yes McT shouldn't be anything more than a squad player - but can you realistically expect more from the academy in terms of impact on the first team squad at any given time?
No we aren't a selling club per se, but player sales is a part of any football clubs business model and we should/must move towards becoming better sellers if we are to compete for glory while being compliant with FFP, and our academy has 100% had a positive impact on our ability to buy players the previous windows and will also probably have that in the coming windows (just a shame the money has been so misused).
In your original post you commented "..our academy needs a massive overhaul, sack the lot that are there at this stage. A club of this stature needs to be producing better or what is the point of having an academy?" which I believe is quite an overstatement and a bit hyperbolic, especially if one actually considers the positive impact our academy in effect has.
You produced valid points, but compared to clubs across Europe, our academy feels it is lacking and in my eyes, from the scouting getting young players and the team scouting talent for the first team, both are atrocious and it needs a shake up.
For example, it is criminal that someone like Martinelli wasn't given more than 4 trials at the club, but is one of the main guys in one of the strongest Arsenal teams in a decade. How did he slip through their fingers? Got to question how someone like Chong showed more than him....
Rashford, he goes missing for 18months and then shows up for 6 to 8 months, rinse and repeats.
I'd much rather we had an academy that could fill in gaps that we have right now rather than splashing huge amounts in the market. We apparently have no striker coming through ready to come in, so we splashed huge amounts on an unproven striker from the Serie A. Neither McT or Hannibal are good enough to fill in at midfield and we are hoping Mainoo can lift the heavy load at the moment.
Injury crisis in the LB, had to loan a player in from Spurs, our best LB to come in the past 10 years is Brandon Williams who is not good enough for a team out side of the bottom 3.
No CBs have come through other than Willy, we have rarely seen him and I pray he turns good. There are areas all over the pitch that need improving, but none of the players in the academy are even worth the chance apparently, this isn't a manager problem either because it's been going on for years now.
Barcelona have been sourcing players for nearly 2 decades, although Messi is one in a lifetime type player, there isn't any excuses as to why they are consistently bringing in players from La Masia to fill in.