Originally Posted by
s0ssos
If you look at the actual modern usage of the word "should", you will find that most people find impolite
"Should" means "ought to", "supposed to", ... Like you are telling someone what to do, as if they were a little kid.
Now, if you used "shall" it would just go over most people's head.
IME, in the UK at least, the construction in question is common and not at all impolite. It simply means something like "it's most likely that..." or "it is natural to think that...." Furthermore, the "should" applies to the speaker, not to the listener, so it is not telling the listener what to do.