In the positive aspect, the guidelines keep everything on the platform very cohesive.
The way apps are on mac os is different than the apps on windows. For example, if Microsoft office
on mac was the same way as on windows, it would lose it appeal. In addition, intuitively, it works
the same way across the board. It benefits the users not only aesthetically but psychologically.
All the same shortcuts for the same function. In the mac os, we know that the basics function of
the applications is all always on the menu bar on the desktop and not the app itself. If you need to
save something, look for tools, or edit, etc. the categories are usually placed up there.
The negative effect that comes with the guidelines is that all the apps might not made for a
certain OS, so, by following the guidelines, actually limit the adequacy that the app can actually offer.
It might work better on other platforms because the freedom of design and coding program.