The reverse of this, however, has impacted our hiring process in the past. We never really looked for things from someone's portfolio or personal website as a way to judge their skill level, but we have been much more critical on some prospects due to their personal site.

I won't personally judge harshly if it's not prominently displayed on linkedin, or easily searchable. But we've had several candidates that had links to their personal website on linkedin, or even in their resume, and they were ATROCIOUS. I just find it crazy that someone would advertise a personal website that was poorly written. If it's a personal project you don't work on much, then don't show it off on your professional resume.

But I agree with your initial point, we never really used portfolio sites to determine if they were worth hiring.