So should people not be allowed to write on a personal blog or in an online publication for the public exposure/other knock-on effects relevant to their day job? Because all those people are, at some level, competing with freelancers and other writers.

(I've actually had conversations with professional writers about this. Their general take is that ship has sailed.)

Now, to be clear, organizations trying to get you to do something that you're typically paid to do is absolutely a pox. But there's a difference between a consultant being asked to give a free presentation at an event "for the exposure" and doing so voluntarily because they've made their own decision that it's a worthwhile investment in lead generation or whatever.

To give a personal example, last year I published a new edition of a book. It wasn't for free but it might as well have been in terms of earnings per hour, but I actually wanted to do that. But if you want me to write something for your corporate blog, you're absolutely paying me and paying me pretty well.