Not really S&L, as I have said before I fly both in the UK & US. I fly from 2 clubs in the UK, both happy after a 1hr checkout.
I have also watched UK trained students completely lacking in ability, so by your inference you could conclude the same about UK schools!
There are of course those instructors who just instantly take a dislike to pilots who have trained abroad. This has been brought up by a few people on this board, I remember one post (fairly recently), where an instructor turned round to a pilot and said 'Pha well thats x hours then!' - before even seeing him fly!!!
There will be schools where the training is not upto standard but these will get weeded out and you only have to look around on here to find students/pilots pointing out good/bad points about schools.
If you are going to tar all non-UK trained students with the same brush then I think you ought to consider swapping professions...