In a country with congested airspace such as the UK, it is vital that a lost pilot gets help quickly before wandering into controlled airspace and getting in the way of all the lager-lout people-tube drivers on their way to Oybeetha from Lootnairpawt or wherever. Acknowledgment of their predicament and prompt use of the D&D fixer service will achieve this - but pilots need sufficient confidence to use it correctly. For that they need some practice.
Last time a student and I used 121.5 for a Practice Pan, it also assisted West Drayton in locating a duff site.
The inconvenience to others of Practice Pan calls can be minimised by off-air practice first; students WILL still need the odd practice though. The only alternative would be vastly improved LARS in the UK - which is unlikely!
The arrogance of some so-called professionals whining about students practising safety procedures is unbelievable!!