It seems to me that this is another occasion in which Elly's fear of the outside world make things worse for herself. Just as all she really knows about Boy George is that he makes music that terrifies her because it's not familiar and thus not safe, all she really knows about video arcades and punk music comes from alarmist sources that confirm her fear that the world is coming to an end. Best not to do anything new and scary lest she invite either the chaos her conscious mind fears or being laughed at for being a dimwitted old stick-in-the-mud who's too stupid and cowardly to keep up with the times that her subconscious mind fears.
It's also best to ignore the fact that her children are the ones who have to pay the price for her lack of anything like a spine. She might think that she's thought of as an exemplar of common sense in a world that's spinning out of control but my gut tells me that her time being described as "that nut with the sandwich board" is not the first time she's been thought of as a panicky ignoramus screaming about something that she knows nothing about. The end result is that her children have things worse because they have to absorb grief when she goes on another battle to the death with windmills.