The standard command processor in a typical Linux package certainly isn't part of the kernel, but I'm sure I don't have to tell you what would happen to the product if you simply removed that command processor without rewriting the zillion things that depend on it.
First off, which command processor are you talking about? BASH? CShell? ZShell? etc? that's actually the perfect example of modularity. you can easily swap in whichever shell you prefer.
Second you HAVE to have a command processor, otherwise you can't execute commands! On the other hand, you can execute commands without an HTML parser. We've done it for many years before MS decided it was simply too important to leave as meerly an add-on program.