There should really be some rules about that.

We signed appiah at 21 years old. I'd hardly call him a youth player.

It's a challenge to blood youngsters in the prem unless they are really good. Clearly ours aren't that good.

Taking appiah as an example he's been given ample opportunities on loan and best he has done is a few goals in league 2. Why should we be giving him a chance?

Call me a wise old sage, but watching Ladapo's awful performance in the pre-season friendly at Bromley, I had a feeling we wouldn't be seeing him in the 1st team

Made in Bromley

I wholeheartedly concur with these sentiments.
I had this discussion with someone only the other night.

One of the youth team coaches (John Salako?) spoke at a supporters trust event a year or two ago. He was probably more candid than he should have been but, without exactly saying the current crop (at that time) were crap, he did come pretty close. I suspect they still simply aren't good enough. You can argue about why the academy isn't producing the right quality but the fact is it isn't. As others have pointed out, very few clubs have cracked this problem, Southampton probably are the outstanding exception to the general rule.