There's an excellent yak on Bill Sledzik's Tough Sledding blog about whether PR is, or is not, a profession, and whether it matters.
Sledzik got the conversation off right by saying the trade meets zero of five common criteria for "professions," and his readers make the rest of the points, except one:
Nobody points out the advantage of not being a profession: You can have more fun than a professional! You can make stuff up as you go along! You can do it your way! You can wear funny hats! You can do stunts! (There's even a name for them: "publicity stunts.")
And whatever you do, people who call you unethical are likely to be seen as prudes, or jealous of your success and visibility!
If we're not going to be a profession, let's be a party.