WASD is "pro-mode" but not everyone wants that. I certainly don't!
Honestly, the issue is more that we've made something that CAN sort of quack like a duck and because of people's expectations, they set up the controls that way and find the controls heavily lacking. I do agree that the controller support could use some work, but playing the game in analog mode is like trying to play Super Mario 64 in an emulator with only a keyboard. Sure, you can do it, but it'll be painfully clear your controls are suboptimal. Analog mode is slippery and has a camera bad enough that we jokingly compare it to Sonic Adventure's camera. In retrospect I kinda wish analog never existed so people came in with a blank slate and we could sculpt people's understanding of the controls without expectations that it'll work like Sonic Adventure.
SRB2 really is an entirely different animal and I don't consider using FPS controls to be "pro mode" as much as actually using an analog stick to play SM64 like it was designed for. You're welcome to play it with analog, but just remember that it's suboptimal when you encounter things that seem more difficult than they ought to be.
This is fixed in the 2.1.1 patch posted earlier in the thread. Update your copy and that crash won't happen.
The reason analog mode doesn't work in netplay at all is because the camera, and all the variables attached to the camera, are client-side. The server of the game does not have any knowledge of how you've chosen to display your view, which works fine for the normal control scheme because it doesn't care about the camera's location. Analog mode uses the camera's position to determine which direction your movement keys correspond to. Since the server doesn't know where your camera is positioned, it's impossible for the server to know which direction your inputs would correspond to. This is why analog doesn't work in netplay, and it's impossible to fix this without completely rewriting the netcode to transfer camera information.