I know several people who have gone down the supposed Electrical Trainee route, one is a former finance broker in the city and lost nearly everything in 2008 when it all went belly up. He did a group of courses in 2010 with one of these training providers and is a DI with NICEIC
He knows his limitations, but having worked with him he is methodical, safety conscious, sits down and does his calculations for voltage drop and cable loads etc.. His work is of a very high and good standard.
Another person is a fellow ex serviceman who after having some mental health difficulties after Iraq. Struggled and had his DI training paid for with one of the training warehouses, he was a helicopter technician in the forces and again his work on electrics is excellent, he is very good at testing and inspecting and methodical and safe in finding faults.
Both of these guys I would sooner have working on my own home or my families than supposed time served apprentices or people with all the paper but no brain cells. Neither could go down the apprenticeship and 3 years of training route, Both know their limitations and work safely within it keeping them and customers safe.
Qualifications in themselves mean nothing, experience helps, but there are many competent DI's out there with little proper experience who i would sooner see working than so called qualified electricians doing poor and unsafe work.
Part P in itself is well intended but a part p building regs course alone wont get you in one of the schemes , we joke about how easy it is, but if you speak to the regional assessors they do refuse quite a few applications to the schemes. Its just nobody ever admits to it and carry on doing jobs regardless!!
Overall its made the industry safer! as the Electrical Trainee's are at least supervised even if minimally and that is better than somebody doing whatever with no oversight. Yes, you get some working beyond their skills and ability but these are far out weighed by the people doing things according to regs safely and appropriately.
I think anybody paying around 3k for a group of courses plus more for testing kit and tools to enter the industry as a DI doesnt do it lightly, thats quite an outlay for somebody to be a cowboy or somebody who doesn't care about their work and safety.