Everyone who hates the rule is worried about a robot on your team becoming disabled and then losing all of the points in the second match. Using the same thinking what is to keep the opponents robot from becoming disabled in the second match similar to what happened to your own in the first?
A great robot, capable of winning the regional or national event should: First of all not break, it should be build robustly. Second, if it does break you should have designed sub assembly's that can be swapped out to bring it back into competition very quickly (Such as spare gearboxes)
As for teams being malicious and going out to break you robot, bring it on, every team here should know that there will be big time interaction this year just like last so you better armor up all of the vitals on your robot. (Just look at how the kickoff showed a powerful robot block the other from the stack and from getting on the platform easily dominating the match.)
