Recently Matt Cutts, head of Google's Web Spam Team started a small firestorm by saying this:
"Okay, I’m calling it: if you’re using guest blogging as a way to gain links in 2014, you should probably stop. Why? Because over time it’s become a more and more spammy practice, and if you’re doing a lot of guest blogging then you’re hanging out with really bad company.
Back in the day, guest blogging used to be a respectable thing, much like getting a coveted, respected author to write the introduction of your book. It’s not that way any more"
Suddenly, people started questioning the value of guest blogging, even asking if they should stop the practice.
Matt is looking at guest blogging through his Google lens - in other words using guest blogging strictly as a vehicle for creating inbound links ans their resultant Google juice. From that perspective he may be right (I have no idea how google could algorithmically enforce this.)
On the other hand, if you are guest blogging first and foremost for a human audience (instead of Google) then it is still a great idea. It is a great way to increase you exposure and introduce yourself to a new audience.
If you are guest blogging and put a link to your own blog/website at the bottom Google may not follow it but humans certainly will.