TonyStill: I agree with your point completely. I suppose though, looking at the flipside (ie probably somewhere nearer MW's viewpoint), he's no doubt spent a lot of time working on it, and would like to recoup some money for his efforts (even if small). In a market where most people who need to edit Artworks file own a copy of Artworks itself, your options are really only to extend AW (which he's doing,) or to reach a userbase which doesn't buy AW but is prepared to spend money to support the products.
Where this would open up a market was if there were a reasonable repository of transparency-using, AW-based clipart. TechWriter users would therefore be the obvious purchasers of such a product - so they could use nicer clipart in their documents. Select users would also benefit because you could use ImageFileRender to put Artworks files into, well, anything that supports IFR.
I guess the likeliest source of quality clipart files would be to convert them from other sources. Makes a reasonable market for a conversion tool to Artworks from other vector graphics formats on other platforms then, I guess .