Yes, same here regarding the avoiding of confrontations, and yet willing to confront those who, for instance, show some character issues on the surface that are offensive. Perhaps in many cases it's because those who avoid confrontations are often sensitive to critiques and rejection and/or are empathetic, so if they feel either their or others' very nice, persistent and reasonable attempts to stop the confrontation or severe character flaw went unnoticed, unappreciated or went nowhere, or if they feel the other is showing, for whatever reason, they could care less about controversial remarks, behaviors or actions that hurt others, or if they do not seem to want to avoid confrontation in a calmer and more rational way, frustrations in me can build or a need to react can occur.
As the one who avoids confrontations likely had much pain in the past from rejections and criticisms that stung, and as they often can be bothered when others are critiqued and rejected too, this may mean sensitivity to those who are not this way but who choose to be very controversial or confront. So, if my patience, or nice attempts to play peacemaker or mediator to a conflict was not working, as I felt the other(s) was not listening to sound reasoning or approach, which could adversely affect others who are watching or listening who could prefer more rational and constructive attempts too, then I am the type will stand up for right versus wrong, or to try to stop prolonged pain in myself or others.
Yes, this could cause confrontation, but my rationale would be sometimes you need to show some frustration at someone who was being a jerk--male or female-- for the other(s) to listen, and for others to be protected, if other attempts by others or myself were not solving much, if they showed a pattern where they did not have the ability or desire to resolve things in better ways. Usually, I will grin and bear unpleasant things as long as possible hoping things resolve, or let others get involved to see if that helps, but if I feel nobody is really wanting to intervene or help there, or if things repeat or persist, it can be a strong urge to do something, and often this means to express frustration, but in a PG at worst way.
As I am a perfectionist and am very vigilant as well, I admit that I have high standards for myself, in terms of my efforts and in being my best, so I admit I will notice character traits--good, neutral and bad--easily in others too. This also though means I believe in taking responsibility for my mistakes and wrongs in life, but preferring others also giving their best efforts and being accountable too, for those things "within their control." And yet this contrasts with my shown easygoing and calm baseline nature, and as usually I am accepting of all and see the good in them. But, when I feel some bigger confrontations are occurring or will continue to occur because of someone acting in an abrasive. selfish, or unfair way, or if they seem unaware of the harms they are causing, or refusing to take accountability, yes, I will confront those rare times, hoping it will result in less future confrontations if that other could learn of the harms their actions cause.