Twitter blog using blogger blog

I have just visit blog.twitter.com and found that it is using blogger.com hosting blog. I am gettng surprise to see that they have not put any link to blogger.com. I guess if they use wordpress blog then they must use a phrase 'Proudly powered by wordpress'.

My question is why twitter authority have not mention any acknowledgement to blogger. They should write a single line like me. I wrote a single line at the bottom of my blog "Powered by Blogger." This is a common courtesy to using any free service online, but twitter failed to show it.