I used to think it was an absolutely awesome for a laptop to have an rj45 - something missing from the VAST majority of thin & light ultrabooks. I still think it's useful. This week I used a laptops rj45 to figure out that the connection to a switch was working but not the connection from the switch.
However one thing I realised is that if I'm ever repairing computers I'm going to be carrying a toolkit with me regardless. If there's an issue with some locations network and/or devices I'm going to want a console cable, an ethernet cable, cable crimpers, a drill, screwdriver set, usb drive, velcro ties, spare parts, label maker, a whole bunch of useful things. I have a backpack just full of useful stuff. If I'm always going to have tools with me adapters aren't a huge burden.
Additionally most of my clients exist at geographically disparate locations. If I ever find myself physically connecting my laptop to stuff I ask myself where I fucked up. If you have to physically move yourself to a broken device and plug a laptop in to figure out what's wrong 90% of the time it's reflective of not setting up proper remote management tools. It means you have a more fundamental issue that wastes money on expensive labour and risks downtime. If I can't fix your systems with an instagram machine with zero adapters it's reflective of a deeper issue. Personally I'd rather use an off-the-shelf thin and light that's portable and inexpensive.