The blurring line between public relations, advertisement, and marketing communication

A couple of years ago I suddenly nurtured an interest toward marketing communication, believing it is a new, distinctive career helping customer "connect" with what the company offers. And yes, the "marketing" looked like something that could work as a Plan B for sneaking into other fields if I wanted to cop out.
As I studied further, surely the reality started to look much more messier than my clueless imagination.
My tentative conclusion was "Marketing Communication" applied in real-world was a shelter for advertisement and PR companies trying to look glorious by snatching the ubiquitous-yet-still-powerful "marketing" title and trying to appeal to the customers by claiming they are helping the world with better "communication".
In short, a glorified advertisement job.
Whether it is good or bad, I put aside the morale issue and asked myself – "Can I put my heart in advertising something?" The answer was obvious; I was never good at giving people fake dreams. Or put it in another way, I was (still is) a very bad liar. Not that I am always honest, just I wasn’t born or trained with that skill set. Not much of a heart problem.
Becoming a journalist looked too far fetch, and – if it was about truthtelling, being a professional journalist didn’t look like a requirement (the blog movement after 911).
Finally the job direction settled into an abstract but more down-to-earth "making complex information easier", thus, a technical writer. Low threshold but lots of job opportunities.