Because Google Fiber HQed there. Come to Houston, where you'll pay >$200/mo for 5Gbit if AT&T covers your area or MUCH LESS if Ezee is an option.

What provider has 10G? Highest I've seen is 5. Genuine question - I'll keep them in mind next time I move across town!

You can get 8gb fibre for around $65/usd a month in Toronto.