This one is so easy to overcome. Firstly, you can right click on the instance of terminal in the favourites and select "new window". Admittedly this does double the number of required clicks from one to two. That's why I am using an extension that permits placing shortcuts on the top panel, GNOME 2 style. Using the panel shortcuts always opens a new window for any application. I use multiple non-maximalized windows all the time and have no issues. Extensions in general, and I am using several of them, have made GNOME Shell usable for me. In fact I have gone from hating it to kinda almost sorta loving it.

or a fourth season episode of The Wire?

You should have kept reading as you appear to not know what Ubuntu is.