There are (technically) lots of problems with how Audacity handles multiple open projects. Ctrl+N is a relatively safe way to open more than one project, but there are still many problems that need to be resolved. Getting this “right” is very difficult, but it is something that the developers are aware of, so in the short/medium term there may be some cutbacks on multiple projects so that in the long term multiple projects can be handled correctly and safely.
But this “feature”, that’s not even a feature, is something that actually was working in all the older versions. I don’t understand why you say all of that now. I’ve always used the quick shortcut in the taskbar to open new projects and never, ever had a problem, and I’ve been using Audacity since 2009, and a LOT. Specially this “feature”.
It’s no use going on about this. There is a bug report open for it. The changes were made primarily for Linux where there was a long-standing problem that once Audacity was running, you couldn’t open a file in a new Audacity window at all. We wanted to make sure these changes were safe.
You know that you can change the CTRL + N shortcut in Keyboard Preferences, don’t you? So if you need to open the new window with one hand, change it to a single key shortcut.
Gale
Oh, version 2.1.2 still didn’t fix this bug we have in Audacity for Windows since 2.1.0 version. 
Not fixed in 2.2.0 
Could you take a look at it?