Well let's see...
First of all, it's pretty insulting that you would suggest that Worlda maps aren't 'original' and reminiscent of 'plagiarism'. The only part of the map that is copied is the basemap; I know for a fact that myself, Iserlohn, and I'm pretty sure Beedok (and B_Munro, though his style is wholly unique) draw our borders pretty much from scratch. I do it by hand; pixel-by-pixel. It can take ages.
As for "Why not try new things?", what exactly are the options available? Either you use a pre-existing basemap - Worlda or Q-BAM - or you create your own basemap, which you'd need to use Photoshop, Gimp, Inkscape, or some other image-editting programme, the likes of which, as I said before, most people don't have the time to work around. I've attempted Gimp on numerous occasions; never posted any finished results, because I simply didn't have the time to properly get my head around it. I can't afford Photoshop (Jesus, who can?) nor do I particularly trust downloaded versions, and from what I've seen the interface of Inkscape is simply confusing.
I, like most people, try to make my basic MS Paint Worlda maps as interesting as possible, and I put a lot of effort into them, and usually I'm pretty happy with the results. You'll forgive me for sounding pissed off, but frankly it's just a little riling when someone comes into the Map Thread and starts telling me that my maps are 'boring', 'unoriginal', 'borderline plagiarism', that I need to 'try new things'.