It's NOT a "con". All sites are pretty clear on how they work - artists just have to read the contract/TOS carefully.
Yes, my "tone" was off... Yes, I should have put things more diplomatically... However, I'm not angry with the site mentioned. I was disapointed that one particular site was promoted --- as there are many out there. I was aslo disapointed that the particular site (and concept) was made to look like the second coming of Christ, which it is not. A lot of people never reach the $50 so all they accomplished is to feed someone else. 50 cent or less for the use of an image might not be enough for some artist here (read the contract/TOS carefully before signing up).
Look at Jolande's post: research, hard work and a great portfolio will sell images, and the money is banked as with Adsense.
The big difference with micro stock sites is that you are banking on your physical work and copyrighted material - a real commodity. Adsense is just one advertisement method out of many. Another big difference is that you control the ads on your site - a stock site OTH can remove any or all of your images at their discretion (e.g. if it's not selling fast enough according to abstract rules they define for that particular day).
It's not for every one, which I'm sure many members are aware of by now. Please don't sell yourself short - or quickly - research before deciding if to sign up or not.