Take kids, for example. My gym doesn't have childcare on weekends or holidays, so I definitely can't take my 2.5 year old with me, but what about the baby? I decided to give it a try on Boxing Day and ran it by the girl at the front desk. She was fine with babies in carseats or equivalent, just not kids running around getting into things.
I decided to do lower body, as upper body would've been more difficult to find safe exercises to do with the baby.
I got a killer leg workout, during which my baby fell asleep! So I decided to prolong my workout rather than waking her up. If she had been at home I would've rushed home to her and likely cut my workout short.
There are plenty of legitimate reasons to not be able to make it out for a workout. One of my resolutions is to look critically at whether my "reason" is really an excuse.
Happy New Year!