The primary aim of my blogging platform choice has always been archival. Hosting my own blog and having to update certain aspect (i.e. security) to simply keep it running are not-inconsiderable distractions.
There are other things, such as storage, that merits trying out the bleeding edge (ZFSonLinux). But when portability is possible for a range of commodity services (blogging platforms), I chose one that is (presumably) Too Big to Fail. Though Blogger may yet one day meet the same fate as Reader.
Lack of CSPRNG Threatens WordPress Sites