Do goalies ever get pulled because of their own play, or often, seems usually the team in front of them is having such an awful game it's like the coach is just doing the humane thing, or hoping his skater will somehow pull their heads out of their ...
Every time is unique, but being that NHL goaltenders are NHL goalies for a reason (they know how to stop pucks), its rare that they get pulled for missing on easy, low percentage shots.
Majority of the times a goalie is pulled is due to the breakdown of team defense in front of the goalie which leads to high percentage scoring plays (and usually results in goals) and is a tactic used to send a message to the rest of the team.