People use Docker because it's easy to use and easy to get support, and it's easy to hire people who have experience with it. Similarly, you could roll your ow

People use Docker because it's easy to use and easy to get support, and it's easy to hire people who have experience with it. Similarly, you could roll your own Dropbox solution with rsync, but good luck teaching your Mom how to do that when she calls you on the phone and she just wants to know how to sync her photos. By the way, it's pretty difficult to write a binary package system that is reliable, distributed, easy to use, easy to troubleshoot, well supported, and easy to sell to both the engineers and the execs at a company. Docker has done that. It's not a small thing.