Well, I thought the heading was evident enough it isn't a tax.
But as I mentioned before, you are free to have an opinion, for I wouldn't start a discussion thread if I insist everyone sees it the same way I do. In fact I applaud you for voicing up, because this is how we keep the forums active.
The permit applies to event coin guns.
Also, I know some players would stack up on the permits, but think about it - a permit given to a player via trade would mean that another player has 1 fewer permit to use. Which means to say that, even though there are players who stack it up, there will be fewer players who could stack up.
Take this for example, there are 5 players with each 10 permits. One player stacks his permit up to 30 after trading with two others. So, the permits among this 5 people will still be 50 (as is the initial), and now there will be 3 people with permits as two have already given away their permits. This also helps to regulate the shots, because either way, its either each of the 5 players pk or just 3 but with more shots.