It's really just for convenience. I build a lot of drupal sites and often need to run a lot of them at once locally.
Instead of putting each one on it's own port (hard to remember) or starting and stopping VMs or containers (tedious), I just use a subdomain like http://projectname.local.computer).
I'm a contributor to Aegir, and created the aegir docker containers, which default to aegir.local.computer for easy testing. When I create sites in aegir, I don't have to set any DNS if I use a subdomain of aegir.local.computer, I can just visit node/add/site and fill in the form and get a site. Great for Aegir development. See https://hub.docker.com/r/aegir/hostmaster/
I'm also creator of devshop, a more "cloud-y" version of aegir which gives each site a domain automatically, so local.computer is really great for developing devshop as well. http://ENVIRONMENT.PROJECT.devshop.local.computer
I've also got a CLI tool for launching drupal sites locally in docker containers called Terra. It uses jwilder/nginx-proxy to route requests for domains to the right container, and makes dynamic domains like devshop. So *.local.computer is useful there too.
Instead of putting each one on it's own port (hard to remember) or starting and stopping VMs or containers (tedious), I just use a subdomain like http://projectname.local.computer).
I'm a contributor to Aegir, and created the aegir docker containers, which default to aegir.local.computer for easy testing. When I create sites in aegir, I don't have to set any DNS if I use a subdomain of aegir.local.computer, I can just visit node/add/site and fill in the form and get a site. Great for Aegir development. See https://hub.docker.com/r/aegir/hostmaster/
I'm also creator of devshop, a more "cloud-y" version of aegir which gives each site a domain automatically, so local.computer is really great for developing devshop as well. http://ENVIRONMENT.PROJECT.devshop.local.computer
I've also got a CLI tool for launching drupal sites locally in docker containers called Terra. It uses jwilder/nginx-proxy to route requests for domains to the right container, and makes dynamic domains like devshop. So *.local.computer is useful there too.
https://github.com/terra-ops/terra-cli https://github.com/opendevshop/devshop