This is partly historical. When MultiFinder was introduced to System 6, the Mac's primary difference from the PCs of the era was an emphasis on mouse manipulation, instead of keyboard manipuation (via DOS's command line, mostly). It was expected for end users to use drag-and-drop to move information between applications, instead of using the clipboard. (Something that Apple themselves didn't fully come through with regarding APIs until System 7.)

Since drag-and-drop requires visible targets to work, and users were expected to have to see data from two or more apps at the same time, it was considered "rude" to take up the entire screen. (Even apps that tried to do so were constrained by the OS to provide a 4-pixel gutter around the edges of the screen so the user could always option-click the Finder to the foreground.)

The notion that you only do work in just one app was considered "missing the point" for multitasking, which is part of the reason the original "Switcher" metaphor for multitasking in the classic Mac OS was abandoned.

http://folklore.org/StoryView.py?story=Switcher.txt

Upshot: Apple's UI designers seem to regret adapting the newspaper publisher's concept of the clipboard, and have been trying to invent workarounds ever since, probably because it's a form of "hidden state." (See iPhone 1.x and 2.x for a more recent example.) The only time in recent memory Apple acknowledged the validity of a clipboard model was when they tried to adapt it to a "publish and subscribe" dynamic system in System 7, only to give up when implementation and UI complexities with the concept rendered that unpopular.

I feel the same way about maximize. If you complain about it, someone who defends every Apple decision will say "why would you want to do that? It doesn't make sense."

http://news.ycombinator.com/item?id=600389

Anyway, I downloaded something called Right Zoom that changes the behavior of the zoom button (which I find practically useless).

http://www.blazingtools.com/downloads.html

If you'd rather not use a proprietary program from a company that makes keyloggers, check out WrongZoom (downloadable link in the readme): http://github.com/spicyj/wrongzoom/tree/master

I don't defend every Apple decision... but this is more a case of history with Apple creating a windowing paradigm before Microsoft did...

http://www.reddit.com/r/apple/comments/8pejm/i_love_my_mac_a...

You can drag'n'drop the file too.

And for blinking ads in the background try either Option-Command-H (Hide everything else) or Spaces.

Yes I know that's not the answer you want, but just in case it helps you or anyone else.

For some apps (ff for instance) holding cmd while clicking (+) maximizes like in windows.