G,
Not surprisingly I don't agree with your view on this one.
If you only spot the ditch below 500ft you have obviously got to work on your field selection. Unless you are very proficient in sideslipping, starting one at 500ft is going to be a recipy for disaster.
If you want to practice landing without the visual clues of a RWY you can go to some grass strips/airfields.
The notion that one can only do a meaningful PFL if you continue into the flare is not only incorrect but also does not encourage a lot of people to do them as they are worried about breaching rule 5 or being alleged of it.
I put it to you that if a pilot can consistently pull off a good landing on the spot from a glide approach and they are able to set themselves up consistently from a random 'pull the power PFL' to 500ft that they are likely able to pull off a decent FL.
FD