CM, to each their own. Not everyone has manners and not everyone knows how to be sensitive and proper. If I found myself in your situation I would just think “your loss”. While they think “my gain”. Each person has their own perspective. “They” work hard on their midos not realizing that they actually insulted you by not doing it properly or in a sensitive manner. YOU were insulted instead of realizing that you need to give them a little bit of credit for their working hard on their middos. It all depends on which window you are looking through or which camera angle, so to speak, you are looking through. From their angle they are doing good, from your perspective they are “rude”. It is a matter of point of view.
So how do you change your attitude? Pick your chin up off the floor and understand it has nothing to do with you. Please don’t compare them with goyim, because while it is true that a goy will have the common sense to hold the door for you, or to get in the elevator with you, a goy might make you feel uncomfortable as well because HE might stand too close to you, or might be wearing pants that are too tight, or she might be wearing clothes that are just barely covering, or speaking very foul language, etc. Anyone can make anyone else feel uncomfortable if you allow them to and even if you don’t, you just can’t help it. Ignore the things that don’t sit right with you and just chalk it up to different people conduct themselves differently.