Cracku mocks and sectionals should show the number of test takers so that we can judge ourselves in a better way.

This whole process will become another DILR question altogether ;)
Nonetheless, why cracku can't show the exact number? I don't know what the issue is with that!

You can get a rough idea by taking a look at your percentile and your rank (based on your score). A matrix of rank vs score is given in the analysis section. I have noticed that 1000 people (500 in the recent ones) take a particular mock within 2-3 months of it going live and this number might increase to 2000 (for the same mock) as November inches closer.