IO540, I agree.
However, the rational behind the adoption of best glide is to give you options. My view is that this is justified (at least in part) as it can take a while (relatively speaking!) to assess the best option so initial height is always not negative. Also, getting into to a field you are on top of is not that easy. You could spend some time gliding around which makes judging the height(s) quite tricky because it is harder to assess the relative angle. The other, and possibly better, option is not taught at PPL, but at CPL which is a Vfe and gear out spiral dive (taught primarily for the engine fire scenario, but I was expected to use it whenever). This can require quite an aggressive level of manoeuvering compared to the usual stuff that PPLs are expected to do, but in my experience is much easier to judge for getting into a close in.
Personally, I find PFLs the hardest manoever to complete with a satisfactory level of confidence in the end result. Any situation is going to be tricky, on balance I would go with the received wisdom and go for height first.
On the subject of Mayday. Unlike the Twin Driver scenario, I doubt there is much ATC can do to help. I would say that Mayday is the last thing to do once you are 'locked' on to a field and stable. Trouble is you will probably be below the best height for any RDF.