personally I though that the splat wall was kinda cool...
but that's because I don't check out many art sites, and, well it was kind of ska-punk esc...
TBH I think that it'd only really be my wall paper for a day, before I was, well bored with it...
Don't get me wrong, I mean it's not that it's not done well, it's just that it's not interesting. (and it's been done a lot before).
Now, (not being a big PS user), I didn't know that there was a splat brush... but a quick google image search shows just how many other simillar pictures there are,
TBH, whilst I think that they could have been a little nicer about it, I don't blame them for shooting you down.
Rather than just not post however, you should keep working at it and go back there with something better.
as a contrast
(this is my current wallpaper)
now don't get me wrong, whilst there is not exactly a great load of things happening in there, I find it strangely interesting, and very intricate and detailed.
and (other than variations of that picture on that same site), I've not really seen anything like it elsewhere on the internet.