This thread has many posts discussing how parses can be good for self-improvement ... among numerous posts discussing how you can use parses to judge other people’s performance.
Im largely against parses due to the mentality they create. Tanks and healers judged on their DPS as opposed to how they play their main roles, while people complain dancer is a bad job because parsers dont show the impact that non-damage actions can contribute.
I generally find the negative outweighs the positive