Wikipedia defines Engineering as:
… the science, skill, and profession of acquiring and applying scientific, economic, social, and practical knowledge, in order to design and also build structures, machines, devices, systems, materials and processes.
The important word there was "profession." Nowadays we refer to any trade you've practiced for a while (more than 2 years, less than maybe 20) as a profession but that word has an actual meaning:
noun; A paid occupation, esp. one that involves prolonged training and a formal qualification
And there's the rub: engineers are qualified according to a professional standard, and held accountable by a professional organizations. Here's a better explanation about why that's not really catching on in the USA, and how that might change long term.
Engineers build things that people have to actually rely on; no one dies if I make a mistake, and nothing physically collapses (usually). I'm genuinely flattered when you call me one (and I will never stop you if you want to pay me like one), but please don't. Words have meanings. I'm just some slob who lives in the intersection of software development and administrative upkeep, and that's the way I like it.