But their advantages still outweigh your inferred counter plan because nothing actually happens on a neg ballot, just an obscure possibility that something might happen if we leave the status quo alone.
This is where knowing solid debate theory is helpful.
1. Most debaters (and judges) view TP as a policy discussion. (Many people use the analogy of congress, however, that's not completely accurate because the actor in most resolutions is the US federal government as a whole not just the legislative branch.)
2. In a policy discussion it would be rather ridiculous for the federal government to say, "Plan B > Plan A > Status Quo but since Plan A was introduced first and B is similar to it we're going to go with Plan A." In a policy discussion, proposing a counter solution that is better than the original solution (competitive), and can not be done if the original plan is passed (mutually exclusive) refutes the first solution. In other words, if a plan would eliminate the opportunity for the actor in the situation to do something better than that plan is a bad idea.
3. The argument of "the government probably won't pass your implied CP" is rather weird if you understand that the judge you are arguing to is pretending to be the government for the sake of the debate. That should never be a reason for a policy maker (what the judge is pretending to be) to pass a plan that he thinks is worse than an alternative. I think this is what you disagree with. The problem is your assumption that "nothing actually happens on a neg ballot." A neg ballot is not necessarily a vote for the status quo, (if you believed that you would have to decry all CPs as illegitimate) it's a vote against the affirmative team. And the possibilities of what the judge could do after rejecting the affirmative team's plan are endless. The judge could say "I reject the affirmative plan because the status quo is better." Or they could say, "I reject the affirmative team's plan because this other option is better and if this were real policy making I wouldn't support Aff's plan when I knew this better option existed." Both are negative ballots.