To suggest that because you are a current pilot means you have what it takes "brain wise" is somewhat of a stretch I'd suggest.
I'm sure we can all think of people we've flown with who were perhaps lacking in some way and not people we'd employ if it were down to us, despite the current license in their flight bag. They might be a bit thick, not terribly coordinated or maybe just a total w*****. Either way, hours and recency prove little.
Quite what tests are suitable for the weeding out process is of course up for debate and I'm sure will be for evermore.
However, if a prospective employer has decided that a particular set of tests suits their needs then the act of a potential employee preparing for and passing them tells them more about the candidate than simply the results printout. Whether you think the tests are "a joke" or you "can't be arsed" is actually relevant. There will always be times in life (and on a roster) where we feel the same and people will deal with it in different ways.
The ability to just get on with things and leave all toys where they should be (in your pram) is assessable!