I'm trying to think how to ask this in a way that isn't just opinion-seeking, and it's valuable to this site. Hopefully this works:
When hiring UX designers, what drawbacks should I consider in looking at candidates who use online 'portfolio' services like uxfolio to present their work?
Example: I understand it might be a timesaver, but it removes my ability to review a candidate's portfolio site as a sample of their work, beyond the projects they present. Some of these tools seem lacking in effective presentation, also. I've seen several that don't effectively consider mobile optimization. A standalone portfolio site indicates consideration of all aspects of a project, start to finish, and sometimes shows they've had experience with front end development (sometimes preferred in a UX designer).