It should stop because it doesn't give anyone a chance to debate on certain debates for this reason. The debater will never get any challengers because of that rule they will still have an open debate only with a bunch of comments about their debate and nothing is happening ok
By placing restrictions it is no longer an open debate. A debate where only a select group can voice their arguments is dubious. It means that those outside the criteria can not bring their opinoins. Many of them may have very valid arguments that you will never get to hear! To be honest, Im suprised such restrictions are allowed in the first place.
If someone does not want to ague with certain types of people because they feel they will be quick to quit the debate or use poor logic and wording during the debate. They should have that right. Some people also prefer to post an open debate in the comments rather than a one on one debate. The forum has discussions and random comments, but always debates. If the person who started the debate get's no acceptance because his standards are too high that's his problem, not the problem of everyone else.