I could argue that the longer I spend taking my turn, the more time I have to think and the more likely I am to make the optimal choice. Therefore I will always take the maximum amount of time that the rules allow. When do you draw the line and call it abuse if it's well within the rules and I'm simply exercising my right to taking my time?
It's not withing the rules to slowroll.
Not on this site, as I already stated it has been and will continue to be grounds for banning.
Not in the rest of life either. It's about an unwritten contract between all human beings - if you want to have fun together, like playing a game, then you will have to take each others feelings into account. If you haven't already learned that from the rest of life, it's a big problem. Not the kind of problem that gets solved with an additional rule.