Not everyone has problems with the numbers site because they don't want to improve. In addition to percentage numbers, people are also kicking people for many other things that they should have no way of knowing, like number of clears/prog point/boss HP%.

Like for example, let's say I'm extremely confident in mechanic C and don't make any mistakes during it, so I go and join a prog PF for mechanic D, but I get kicked because I've never seen mechanic D due to the fact that my party keeps wiping to someone not doing mechanic C properly and so boss never starts casting mechanic D.

Or another example, let's say I clear savage week 1 and want to clear for my alt too, so I join a clear PF and get kicked because I have no logged amount of prog on that character. Does that mean I should go and join prog PFs even though I gain no benefit from it at all?