What's the fuss over GMail?

So, I'm reading this article on GMail, Google's new idea in web mail systems. It's free, it's email, you get a hidious amount of storage space, and people are getting in a tizzy because it scans emails you send out and ads advertisements to them based on topics.

Why is this such a big thing?

It's part of the agreement to use it. Don't want your email scanned? Don't use GMail. It's that simple. It's not a secret, it's not hidden somewhere - it's right in front when you agree to the service.

Am I going to use it for private email? Well, no. Obviously, that's a bad idea. But I plan to use it for hobby mailing lists - lego, roleplaying, H Beam Piper, Cthulhu, Nexus - mailing lists where I like to let the old mail pile up for a while, and then pile through them in one long concentrated orgy of reading. Instead of taking up precious space on my hard disk, it can take up precious space on google's hard disk - Google can get ad revenue and my fellow Lego/RPG/Piper/Cthulhu/Nexus fans can get ads based on - well, to be frank, I'm rather curious to see what the ads will be.

But it's entirely up to the user if he wants to take the scanning with the free service, or if he wants to go off and use some other service.

So what's the fuss? Can someone explain it?