Why is it dumb? I think you're going to be in a huge minority of people who are going to have the time to put into this on a tablet. Which I guess doesn't really matter unless you're banking on this funding the next BG.
Why does the tablet matter at all? Unless the control scheme is horribly broken, it's still the same game. The website even says that multiplayer between the different platforms is supported.
Also, most of the people on these forums (the tech savvy) probably have a tablet of some sort. It's not as though the only people who own tablets are completely disinterested in rich gaming experiences. Not everyone is going to buy it, but I don't think it's any more fair to suggest that the number of people would would buy this for a tablet is somehow less than the percentage of people who would buy it for PC.
If it's less expensive for the tablet version, I'll just grab that as well, just to try it out.