I understand what your saying. Though I think it's more of how you perceive it.
Gotta love a theme which gives absolutely no freedom what-so-ever and isn't enjoyable at all.
I think this is a bit of an over statement. A majority of themes have plenty of options if you use your imagination. For instance, I'd consider pen and paper to be daily used items. Therefore I think somebody could made a very good signature from an origami stock/render. Perhaps a paper warriors fighting a paper dragon off with a pen. I'm not sure, but I think my point stands in stating that people need to find a way to make the theme work for them. I'd imagine that would also make it more enjoyable. Of course, some people will try say your signature doesn't match the theme. But who cares if your having fun.
This isn't a "job", people aren't paid for this or anything, there is no reason why people should have to "put up" with things they don't enjoy in a recreational forum. It defeats the purpose.
It's not a job, though some people here are hoping to make it a job. You can't tell your boss, sorry I don't like the theme, I'm not doing it. (you can, but it probably won't go down to well). I understand that some people don't want to do it, and they may not enjoy it. But if people instinctly go for the negative view, witout even giving it a thought, It's quite pointless in it's self. Also, people may create some pretty epic things which could be put into a portfolio etc... You may not get paid, but you'd be doing something you enjoy.
I don't want to sound like I'm forceing people to compete in Sotw... I'm just not a great fan of all the negativety of a majority complaining about the theme etc... Even when we suggest themes and we use them themes, people still seem to dislike it. I'm not great at graphics, and I'm quite lazy. So I'd be contradicting my self if I were to say I'd be entering every sotw. I would just like to see some nice pieces which people have made from thinking out side the box.