LB: “Why does it have to be personal?”
I agree. It shouldn’t be personal. Different people have different standards. Also many people are ignorant of certain halachos. Some people are very chilled-out by nature which is a big maaleh in many ways, but sometimes the flip side is that they are inadvertantly not as careful as they should be in their kitchens.
I had a friend whose house I ate in until I spent some time in her house and realized that I can’t trust her kashrus since I saw that she did things that were seriously problematic. (There were goyim who used her ovens and microwaves to heat up their own – possibly treif- food, and then she would use the ovens and microwaves for her own family’s food without covering the food even though her husband told her she had to double-wrap it. And I’m sure many people ate in her house without knowing about this. There was even a seminary that heated up food in her ovens unsuspectingly).
I probably have many friends whose houses I shouldn’t eat at. There are many things that people are either unaware of or not careful about (probably myself included – I’m not sure if I should be eating in my own house). Kashrus is not a simple thing.