That's a lot less to type
For example, amazon.co.uk is !amazonuk - I don't see the meaningful improvement there.
DDG has six thousand of them, most of which don't benefit from a great shortening of the name. To search answers.com it's !answers - that's an extremely small improvement over site:answers.com given the need to memorize a bang for each thing you want to use it against.
Maybe most of them don't benefit a great shortening of the name, but the most common do.
And for the other, like answers.com, !answers is still 8 characters shorter than site:answers.com
You should really try to use bangs for a while, I'm sure you would see the appeal very quickly
This is interesting: it is one way to allow for a better search experience through personalized search options without using data collected about me.