I'm with Gonzo. I'm currently a controller but did, previously, fly professionally, albeit not civil. Could ATC training be better? Of course it could be. Right from the very first point of applying, through aptitude testing and interviews to validation, there could be improvements. Same with flying training. Flying training, as with ATC, varies in quality depending where you go.
I would say that flying instructors are, generally, on average more interested in teaching. Flying to those who do it seems to be more of a passion than controlling, though there are controllers out there who are really passionate about it. This in turn means that instructors may be more enthusiastic,
However the two beasts are different. ATC is very much, by rote, whilst procedures and specific airspace is learned and understood. You can't throw someone in on a busy session and expect them to get on with it. Same with flying; you teach the basics first then you go on to the more demanding aspects.
Like it or not, flying is easier in many respects... you are in charge of one aircraft, ultimately responsible for the safety of it, but guided by ATC in many aspects. You cannot compare like for like the training of the two, but you can take certain aspects from each and apply them