While developers are used to installing features they want, Brackets suffers from the fact that there isn't any built-in package manager and therefore these types of optional features are gated behind a Google search (where most of the top results are questions about support, not the answers).
Actually, Brackets has a built in extension manager. You can find a list of extensions here - https://brackets-registry.aboutweb.com/ - and in the product you can go to File->Extension Manager.
All the extensions in the registry can be installed from within Brackets.
I suspect one of the big detractors from Brackets is that it doesn't [yet] support VIM/other keymaps out of the box (https://trello.com/c/ckAel1Cl/358-118-keyboard-shortcut-prof... ). Additionally it could have set itself apart as a possible thick-client NodeJS debugger, but again not out of the box (http://blog.brackets.io/2013/08/28/theseus-javascript-debugg... ).
While developers are used to installing features they want, Brackets suffers from the fact that there isn't any built-in package manager and therefore these types of optional features are gated behind a Google search (where most of the top results are questions about support, not the answers).