And I did not say in my world!. I said for some text boxes.
I suspect these are Text Fields/NSTextField. Which the normal behavior is to be single lined or wrapping. They support option-return.
If it was not normal, the option + return would not work.
Q: How do I make NSTextField accept the tab key, as well as return and enter keys as line-breaks?
A: It's worth noting that NSTextField supports new line breaks by using Option-Return or Option-Enter. But under most circumstances the easiest solution would be to use NSTextView instead.
Actually not a bad idea at least the others got something along those lines. Timelines are visualized transitions from one state to another. You can actually also display the states as frames instead. Behind the scenes, you have timelines but only if you need to tweak a transition. This mode is part of Google Webdesigner (GWD)
Both of these are probably true . It is a distinction between a "text field" and a "text view/area." I've filed it as a bug - I believe the expectation is that a return key would enter a new line into this specific view.
Note that in apps like Messages that are return-to-send as default this is also how you enter in newlines .