I think its about responsibility and respect. Everything I design and build, I am legally responsible for and in most cases has the potential to kill someone (or lots) if I get it wrong. Intense study for years, then graft to gain accreditation as a mark of professionalism. Deserves the same level as respect as any lawyer. Personally I don't see it's any different than the respect earned by a Master crasftmen of day gone by. The fact is if someone wants to put the same letters after their name as an CEng Engineer it will take at least 8 years of hard work, maybe more.
Of all the technical people I've worked with over the years. The man I respect the most was a Master Toolmaker. I'd say it must have taken ar least 20 years or experience to gain his abilities. Didn't stop people treating him like dirt. Its a lost cause, this type of skill is no longer valued.