Overinflated sense of self worth I think. Also I think it's funny when it says "photography" on a watermark, as if someone would be confused and think its confectionary or something. 🙈
"Oh, these are PHOTOS... thank goodness they clarified..."
I'm in two minds over watermarking. I think it's pointless for amateurs like me - I'm not selling my photos, and while I'm sharing them here, on Flickr, Facebook, Twitter etc. I'm not too concerned by people re-sharing them (even without attribution) and I doubt including a watermark is going to drive people back to my pages. You're better off targeting where you share them so it's in groups or on sites where users and visitors aren't likely to share without attribution, or always including a link to your site/Flickr/FB page/whatever when you share them.
For people in the business of selling their photos it's a bit different. For example, there was a guy at a mountain biking event I visited earlier in the year who was selling photos of the competitors after the event. He shared some more general photos with the organisers and online that weren't watermarked, but the ones of individual racers that were on his site for sale (or that he put up on FB etc.) were lower-res and clearly watermarked. He makes his money for the event off those, and while people nabbing a clean high-ish res photo aren't going to match the quality of his originals, they are going to have something worth sharing online, using for desktops, or even managing small prints.
TL;DR - if you're not selling them, I don't see much point. If you are, watermark away!