I am a cross platform developer. I have spent years developing on Windows, Linux, and OSX. (Also on other OSs, but what ever.)

Debugging with gdb is very different from debugging with a GUI IDE like Visual Studio. And if you are coming form Visual Studio to gdb, then debugging with gdb might seem down right impossible.

However, if debugging with gdb is so terrible, that means that each and every UNIX and all the software which runs on them were developed with this almost impossible to use debugger.

And Linus and the entire Linux dev. community, who rolled out Git almost on a whim, are stuck with gdb and can't come up with anything better.

Can that be true? Or is gdb in fact a great debugger, but with a very steep learning curve?

In my not so humble opinion, gdb is much harder to intuitively pick up than Visual Studio. But if do take the time to learn it, it is just as productive.

Actually in my experience, it is slightly more productive, because it forces you to work slower and think more. This go slower and think more strategy has also made my Visual Studio debugging better. Although if I spend too much time in Visual Studio I can slip into a pattern of less thinking and more break point setting.

tl;dr:

It's good that you are a very experienced game developer, but being a single platform developer kind of sucks. Become the kind of developer who doesn't care what platform they get to develop on.