Why do they dislike it and think it will fail?
I suspect a lot of it stems from the very American principle of government distrust and a tendency to both dislike and doubt anything that has government involvement. Not saying that's specifically people here or trying to be accusatory or saying it's wrong to feel that way or believe that, but I do think that, in general, I have perceived that notion.
Perhaps it's even clouded how I see it.
I guess it depends on the definition of success. Economically viable? I'm far from an expert, but I have my doubts.
Do I think they'll get a good crowd if the show goes on? Honestly, yes. The races at Indy were well-attended until 2005, with the 2000 event estimated to be the best of the modern era (though if you had as many seats at Silverstone as you have at Indy...). If it has a "big event" feel to it, people will come, and to many in America, the USGP will be the "big event" on the F1 calendar and one worth caring about that's better and bigger and more spectacular than all the others.
One worry I do have: television. You're not getting a race on FOX in NFL season, and you'd think the USGP would be the one they'd want on network (meaning everyone with a TV gets the channel) to generate more interest in the event and the sport. Not saying SPEED's a bad place to be, but the ratings and exposure
are higher on FOX.
I believe, off the top of my head, the FOX races score around a .8 or .9 (similar to IndyCar on ABC). The SPEED ones are usually closer to a .3 or .4, but are at worse times (mornings). I'd be curious to see a number on Brazil, which is live in the afternoon on SPEED. The best-rated I can recall, was the 2002 Monaco Grand Prix, which aired on ABC tape-delayed right after the Indianapolis 500. I think it was a 2.2 or maybe a 1.2, I can't really remember but it was certainly huge for them...
...which makes me wonder if they could run the race a bit later. If FOX doesn't have a late afternoon game (a 4:15), the race could run then, air on FOX right after the conclusion of the early game, meaning a lot of people will be tuned in to FOX when it starts so if you can grab them... But then it's no longer on in primetime in Europe. Or do they not care about European figures (the TV ones, not the women. I'm sure the European figure is much more popular than the American one...) anymore? I can never remember which currency is the priority is with Bernie.