Sounds like it's really not about consideration towards strangers, doesn't it?
No, consideration of others is a societal good taught by parents. The fact that an individual "may" not appreciate an offer, which could not have been known prior to an offer ( by the way many still do appreciate it), does not make it wrong. In cases where it is obvious that offense would be taken, no consideration is due- that would be disrespectful. In those cases where an individual chooses to be offended, rather than simply ignore any consideration, I weigh the slight chance of their being truly offended to the absolute disapproval of myself/parents/grandparents for not at least offering.
No different than lying- there are societal norms that are taught by parents that many in our society today do not value- including many in high places. Adherence to societal norms are what define each of us. That does not make them wrong, many continue to do what is right because that is what they were taught.
I have had the privilege of having an outstanding upbringing that taught certain values that I hold dear- consideration of others, taking care of the less fortunate, respect, honesty, integrity, hard work and sacrifice for principles. These define who I am and what I respect in other people. I make no apologies for any of those traits.