When the pay for instructing warrants the grandiose title of 'profession' then things might improve for the rosy-eyed nostalgics out there but it's the chicken and the egg scenario. Fewer PPL'ers seem interested in shelling out extra cash just to instruct at weekends alongside their daily job. Most of the old school self improver instructors were instructing with a view to flying airliners whether you saw it that way at the time or not I'm afraid.
Show me a school who'll pay at least £25'000 a year and you'll see many more CPL's happily instruct for them for the rest of thier lives, and forget all about airliners and hosties.
VFE.