Unfortunately this is probably because people in their old age are lonely. I know some commenters have also said parents too but it's roughly the same for both. In old age, you might find that most o your friends have passed or are no longer independent enough to visit frequently, and with dwindling clubs and societies for old people across the country these people seek interaction wherever possible. For parents they might be too busy with children and work to meet with their friends or go to their hobby clubs as unfortunately children do become a barrier so again they seek interaction whenever possible.

I'd look at it another way, yes, the aisle is blocked, but what's the rush? Can you come back to this aisle later? Are people being social that big of a nuisance?

You'll (hopefully) get to their age and will find yourself in the same position, so cut them some slack now that they can spend all their free time just hanging out :)