Chalking a disc, time rule, 'foot faults', etc....rules enforcement is a huge issue. Pros don't help things by ignoring violations. I've played with people who still flip their disc to mark their lie....most say....I've always done it that way. I let them know the rules no longer allow it. Same with 'tapping' the chains with their putter. Recently, I had someone try to tell me they can use another disc as their marker...come up to their lie, take a second disc out of their bag and place it on the leading edge of the previous disc. They were surprised when I told them that wasn't allowed...the disc doesn't meet the size criteria for a mini marker.
I think three things are happening with rules:
1. rules have changed, but people have played one way so long they aren't aware of the change (players don't get a new rule book when the rules change and the rules books are easily available)
2. players are 'making up'/ignoring rules to their advantage
3. players just don't care
#3 is the worst and seems to be happening the most....and it is noticeable in the pro tour because they are on video. The video can be paused/slowed down to see what happened.
I don't know what the solution is....I've seen people beat their discs against walls to get them 'beat in'. I've heard players say they put their discs in their trunk (Arizona) to get them soft and adjust their shape. Disc golf seems more like a pick-up sport where people play by the 'house rules'. Modify discs? Sure, as long as it isn't too obvious. Ignore time violations? Sure.