Let me Explain....
Blogging Platforms such as Tumblr & Blogger are free for users who wants to have an online presence. Blogging may not the the thing of the past but its the thing of the present and the future. Over the last decade the number of blogs have seen an insurmountable growth. Let me put that into perspective, 'There's a blog born every half a second'. Don't take my word for it ? Read it on CNET.
Themes, Layout, Plugins
Blogger: Blogger does provide for basic themes by default that you can choose from. If you want to skin your own blog then you can either customize it by uploading either free/premium blogger templates available on the Internet.
Control over your blog
People yelling about sayin 'you don't have control over your blog' listen. These free platforms can offer only so much, you can't expect them to offer you their control panel dashboard on a silver platter. That'd be a wreck....
Power of XML | Cross Platform
For those who think once you've started you're stuck with it. You're wrong. You can move around your blog on any platform you link thanks to xml technology which is a cross platform scripting language supported by many blog platforms.
Are you not satisfied with tumblr ? Export all of your blog posts, comments, tags, labels, categories everything to an xml file which when imported to other blog platforms (wordpress, blogger) automatically imports without any fuss. Yes its that simple.
I presonally have moved my blog from tickrnews.wordpress.com (hosted) to wordpress (self hosted) then to blogger (hosted) and haven't had any problems at any stage.
I hope you understand & the next time someone asks you which platform to choose, don't scare them let alone demoralize their Independent thinking.