Has it though... Has it really? And if so - how?
Pay in professional circles is largely determined by the availability of skills, and the earning potential of these skills. I really fail to see how a cable installation guy or a welder calling himself an engineer has any effect on the demand for people with (say) skills in modelling computational fluid dynamics. Or designing bridges that survive a hurricane. Or [insert "proper" engineering application of your choice here] etc
To my eyes, it is simply that people want immediate recognition for their skills and education through their job title. This is little more than mental masturbation...
In a few of the engineering companies i've worked in, the people creating the wealth were paid less that the finance guys sitting upstairs. Considering there is supposed to be a shortage of engineers in this country, the idea of supply and demand doesnt seem to be working very well, lets face it finance people are 10 a penny.