[Mouse wheel zoom as default?]

MS Paint

GIMP

Photoshop

Paint.NET

Inkscape                                              vs.                                              Paint Shop Pro

Illustrator

Aviary

browsers

office programs

 

Billions of users                                  vs.                                              Hundreds of thousands of users (?)

 

Sating your desire would break the workflow of millions.  

 

 

*snip*

Photoshop does have scroll wheel zoom.  it may not be the default (i can't remember), but it's certainly an option.  It may well be an option for everything else you've listed...except Web Browsers, and PDN.

 

edit: spelling.

[Paint.NET is getting noticed!]

PDN getting a little love from Reddit (and some minor berating, as expected from a mixed community.)

http://www.reddit.com/r/geek/comments/e9jah/one_thing_i_love_about_paintnet_pic/