If you have a group of trusted people who you know and trust and would like to setup blogs for them then you can do that with mojoPortal very easily.
However mojoPortal is not designed to be a social networking platform, it is designed for business web sites with social engagement/interaction. You should read carefully What mojoPortal Is NOT Designed for on our about mojoPortal page.
It is possible to build features with less power that would be safer for use by untrusted users, but you would need to build those features yourself, it is not a goal for the project.
Hope that helps,