Not at all. I think, in fact, that the sarcasm punctuation mark is an extremely good idea. How often have we been victims of that terrible terrible weapon of evil minded people who, just for kicks, take advantage of our gullibility. The sarcmark (how they call it) is the perfect solution to that problem. What's more, on top of it being such a good idea, it's cheap too!
Writer aficionado, this is for you! No more complex writing skills needed to express your sarcasm, no more creativity needed to it. Just say it, followed by a sarcmark, and your readers will know that you're actually being sarcastic.
Clearly, a good deal. So go on people! Buy your very own sarcasm punctuation mark*! This will not only help avoid misunderstandings, it will also take away all the fun to being sarcastic!
*Available for Windows XP/Vista/7, Mac OSX, Blackberry... Sorry folks, no Open source here, open source dudes are not sarcastic enough...
Note. This post was, in case you didn't notice, very sarcastic.