What viewpoints are those, for those of us unfamiliar?

Zed Shaw doesn't really like C because it lets you shoot yourself in the foot. This is an OK opinion to have, but then he goes and writes books about C that basically talk about how the language is bad (ok, I guess?) but the then claims he has solutions to these problems, without understanding that the problems he has with C are not solvable within the language (for example, when handed an arbitrary pointer, there is no way to tell whether it is valid).

Casey Muratori is fundamentally at odds with how undefined behavior works in C and has opinions™ on how to fix the language to make things work the way he wants them to, when in reality he just probably wants another language.

Out of curiosity: why do you consider Casey's viewpoint incorrect?

Casey doesn't really understand how optimizing compilers work, so he likes to talk about how they keep breaking his code and that they should just run the optimizations that won't do that.

also arguably quite correct