Sounds like trying to get rid of collective bargaining is the bridge too far.
Without reducing collective bargaining to base wages, the Budget Repair bill is nothing more than a paper tiger. It's Obamacare without the individual mandate.
More likely Walker and the Republicans simply lost the argument. The fact that people (including yourself) are saying he is "getting rid of collective bargaining" is in and of itself an indicator that Republicans simply failed to get their message out. The bill does not get rid of collective bargaining, it simply restricts it to wages.
I agree with you though, it appears Wisconsin may simply be a bridge too far on this issue. The left has managed to piggyback their protests on the pro Democracy rallies in North Africa and the Middle East and come off as the good guys. Further, getting teachers into the streets is almost always a winner for unions and the left. Women, in particular, are sympathetic to them and virtually always cave in the minute teachers start whining and crying. There is a reason the teachers unions remain so powerful.
It has been pretty clear for awhile now the left/Dems/Labor are winning the PR fight here (despite the fact that so many conservatives couldn't see how this was turning out), and it has snowballed and encouraged the Dem Wisconsin Senators to simply stay away and prolong things - and encouraged similar actions elsewhere (Indiana so far).
Walker and the Republicans really don't have much choice but to stay firm and let this play out. If they concede, Walker is finished. Instead of being perceived as something of a grinch, but at least a winning grinch, losing this fight would result in his being viewed as not only a grinch but a loser. The best the Republicans can do is hold fast and hope public opinion changes. The masses are fickle, and very often the low point for any politician is at the height of a major fight for change. If he wins, he can recover. If he loses, he's done - and the Wisconsin GOP could end up damaged and ineffective for several years. Better to stay strong and go down fighting in this situation. If Walker and Wisconsin GOP Senators are recalled they will be poorly regarded only until the Democrats screw things up (raise taxes) - and then Walker/Republican popularity will rise again and this time everyone will understand what his platform will be.