Having an instructor continually flying a forced landing to 50ft to prove (to a student) whether or not the aircraft can land in a field really only has impact value if it is done once or twice, any more than that the student may consider it accepted practice whilst flying solo as well.
Just to clarify, the exercise was NEVER flown by the instructor - always the student - and there was never any doubt as to whether or not it was "accepted practice" for the student to do it solo, as they were specifically forbidden from doing so.
As far as practising into strips is concerned, it considerably devalues the exercise as the student quickly learns the proper cues for the strip being used - cues that are absent if they have to do it for real. Instructors who use the same field for FLWOP practise are really short-changing their students.
A lot of this is personal opinion I guess, I found it to be true when I was instructing, but teaching others to fly is a game that is constantly evolving.
As an aside, I agree that the overall experience levels of instructors is dropping. I thought it might be fun to do some instructing again, put all those thousands of hours of airline flying in Europe to some use. Not for money, not for the hours, just for fun. However, the CAA make it such a complex and expensive exercise that it probably isn't worth it. The local club seems equally reticent to offer any part-time work, it seems they value experience as little as the CAA does.