Doing things alone are only cringe if you're visibly uncomfortable and insecure.
Otherwise nobody gives a shit except people who are insecure to the point of mental illness and will project that insecurity onto other people.

Pic related. If this guy had his legs up, a big bucket of popcorn in his lap and a bright smile for the camera to eradiate confidence, this picture would go from cringe to comfy (except for the people who are insecure to the point of mental illness, they will still cringe)

Who was in the wrong here?

It's only cringe when if person who is alone is visibly uncomfortable and insecure.

If pic related had both his feet up, a large bucket of crab legs in his lap and made a big smile for the camera, this picture would go from cringy to super comfy