I have no reasons to complain about Blogger. I'm, mercifully, free of comment spam and I have no complaints about their reliability, etc.
However, they get a lot of bad press. I'm assuming this means that those who have tried other platforms have found them superior.
I am about to start up a couple of other blogs - one to capture my deep insights into efficient commuting and one to allow me to speak more freely about politics - and so this is a good time to consider my choice of platform.