It depends on the role you're hiring for, but in general I would weight the content of the profile higher than the website it's on. For example, a history of high-quality Hacker News comments would be more compelling than a lackluster GitHub account.
Agreed - Obviously account quality is the key factor. I have heard in recent times that HackerRank accounts can be easily improved implying a high level of skill however a top GitHub account is probably less likely to faked.
