Meta Keywords are transformed to lower case

I noticed that, if I set my meta keyword manually, they are transformed to lower case for pages. For the home page, however they are not transformed to lower case.

So on the home page I have:
Cars, Bikes, Information

While on static pages the keyword are lower-cased:
car, tuning, racing, marketplace

Shouldn’t this be made the same way everywhere? Either preserve the capitalization everywhere or transform all keywords to lower case. But don’t do a mixture of it?!