If they are really worried about the motives of those who pious-sneer, why not simply discontinue that title? Problem solved.
That way, if anyone really wishes to do more, they simply do more. People should seek the point where the next unit just starts to cost more in terms of money, time, and other resources than the actual benefit received. If they want people doing more, they need to raise the benefit so that happens at a higher level. If Jehovah wants everyone doing 200 hours a month, then he should fix it so the maximum net benefit comes around 220-240 hours a month instead of beating people into doing more.
Of course, if that point happens at or below zero, people will not do anything unless they are stupid. You cannot do below zero (unless you count directing people to apostate sites or dissuading people from becoming witlesses as negative time). So, if the point where it just starts to cost more than it's worth is below zero, do zero.