Why should I write CLS compliant code?

I've found a lot of pages about CLS compliance.

I've understood that CLS compliance:

• Is a way to guarantee different assembly compatibility.
• Is a way to declare the high security code

Many peolple write that "if you write code, you should write it CLS compliant." But as far I can read, there is no reason to use CLS compliance in generic software.

Am I right, or did I miss something?