A wider, low profile switch would be less vulnerable but it would interfere with the design and the customizable look of Chucks is one of the features.
If you are handy, there are posts from people who are able to replace their own switches. If I can find it, I'll add a link to this.
As with all
mods, the button can get gunked up. After all, you will spend a lot of time with your hands all over it, often when they have
e-liquid on them. That's no biggie. As for breakage, the buttons might break a bit more often than some low profile ones, but it's not a chronic thing. You aren't going to need to replace your switch every month. I've got my Little Chuck in March 2010 and it still has it's original switch (although I did manage to strip my 510 connector -- which Jeff replaced.) My big Chuck came at the end of January this year and it, too, still has it's original switch.
ETA: People just talk about when the switches break because, as a rule, nothing else on a Chuck ever does.