Obviously, I agree there are too many never-to-be-supported-devices in the ToH, and some of them are even a bit exotic for OpenWRT (perhaps we got rid of the HP printers and the digital cameras already). And old outdated stuff.
When it comes to routers...
if it is a new device from ASUS/DLink/NetGear/TPLink/Ubiquity (and a few more) I think it is nice if it gets added, even if there is no clue about if/when it is going to be supported. As long as it is added with some meaningful information, of course.
if it is about adding a new unsupported device to brands with no supported devices, I agree with you.
It is important to understand that information is not valuable just because someone put it in the wiki. Less is often better. There is wikidevi and other sources.
So some degree... it boils down to understanding the development process. How does a device get OpenWrt support? It does not happen thanks to the Wiki. Often, it seems to not have very much to do with the activity on this forum either. It is like the wiki and the forum are more like inofficial fan sites. Although of course some developers are here. And some people here occationally submit patches.