But from a usability perspective, it seems to still be a "second-class" citizen in the Linux world for lack of a better way to phrase it.
Some applications create a separate set of "windows" folders, so interoperability between them is a pain. Click and drag support, just doesn't work properly. The folder structure thing seems to be really jarring for me, as I figured it would be as easy to use as Cygwin's folders on Windows, but somehow isn't.
Any who, it's not a perfect or exhaustive criticism, but Wine is still not a good "drop-in" replacement, even if it does amazing things.
But it's there for the taking and tweaking! It's the same as you solve your own problems in the *nix world, but it's for the cases where you really don't have any other solution but but to work with the hardware vendor's black-box provided driver. BTW, don't expect that buying Windows will solve your problems (because Microsoft seems to have acquired a taste for moving fast and breaking things lately).
That may be partly true. Partly, because you falsely assume that anyone contributing to ReactOS would contribute to Wine. These cover common technical ground (of Windows application binary support), but from different ideological prospectives.