Tintin not huge? Maybe it's not huge in the US or Canada, but if having periodical reissues of the albums sold along with the newspapers (and being bought in record numbers), having quite a bunch of dedicated books about its history and even having a few museum expositions is not being huge, then I don't really know what's being huge around here

. Seriously, Tintin is one of the most famous and popular cultural icons, at least in my area.
I believe everybody around here would love to see a UY cartoon, but things are more complicated than that. It's been discussed a few times before. There are things involved like copyrights, quality of the series (how much control does the creator have over the final result), and commercial success, which usually comes in toy revenues. As far as I know (not much), if a series doesn't have the possibility to bring back some sort of income in merchandising, it doesn't have many chances of being produced at all (which actually sounds quite logical).
Making a cartoon is quite expensive, and in order to make some money the series must appeal to as much people as possible. I think UY would be a good candidate, but first most people would have to get rid of some prejudices like the use of funny animals or the lack of violence or action sometimes ("You mean Usagi sometimes doesn't fight? Then what's the point? Isn't it an action series?"). Also, since Usagi kills people in the comics, it'd be pretty hard to target the cartoon to children, which would mean the content would have to be toned down, and some of the most interesting stories would have to be dropped in favour of the more "extreme" storylines in which Usagi would fight against lots of bad guys, I'm afraid. Unless the cartoon was targeted to adults and featured somewhere like Adult Swim on Cartoon Network, but I think that's even harder.
I'm convinced the show could be done in Japan, but making it for he US/Canada or Europe is way harder.