Why people still USE ACT knowing their breaking TOS ??

[KageTokage]

Don't you just need 1 person per party to upload the log for the whole party to be registered? Pretty sure most parties in high-end content will have at least 1 person who will log so the actual percentile won't be that much off I think.

Yes, though if you're playing with randoms there's no guarantees that all of your parses are getting logged, nor can you guarantee that people aren't going to be uploading runs where you performed horribly for one reason or another. Unsurprisingly, this often includes deaths caused by people trying to greed or tunneling and forgetting to do mechanics entirely due to being too focused on maximizing their own DPS.

A lot of people use ACT, but don't actually bother uploading anything.

It's a little irksome that you're basically forced to be in a static and to regularly upload parses if you want to maintain a high percentile and avoid being judged harshly by certain individuals (Though as someone previously stated, said people probably aren't even worth knowing /associating with anyways).