It’s sheer laziness. My MBP & MBA are beside the bed. I use one or the other depending on battery status. I have the proper chargers for both but aren’t using them. Instead I have a slightly dodgy Magsafe 1 charger from my 1st MBA. It can charge the 2011 MBP cos it has an SSD instead of a HDD. And it has a Magsafe 1 to Magsafe 2 adaptor so I can top up the new MBA’s power.