If a TODO passes code review, more than one person fucked up.

1. Those apps are simple
2. Those apps target a wide audience, hence have more budget as a result
3. Those apps are made by large, well oiled (you’d hope at least) companies. You don’t want my honest opinion on most small software development boxes. This industry grew faster than mentors became available for the newbies, so many devs including seniors still don’t know what they are doing.

It has a rocky start, and a lot of cruft from that era sticked around.

There are also a lot of horrible legacy projects from the pre-ES5 era which are a pain to work with. Often older projects were coded either before people knew how to do javascript right, or before the devs who wrote it knew how to write javascript right.