I am definitely too harsh with ignoring, my tolerance threshold is too low and I tend to click ignore at the first sight of rudeness or if I get the feeling that someone is picking on me or wants to start a feud. It's hard to voluntarily ignore what you see written in front of you, so making them disappear is easier.
However I wish there was a sort of "quarantine" feature like on social networks, that would make you ignore someone for 30 days (or whatever) rather than permanently. My current ignore list is unfairly wrong because I don't remember often to go and un-ignore at least those who I don't even remember why they offended me.