There's also another difference between amalgam fillings and composite fillings: amalgam fillings expand slightly when setting while composite fillings contract. Thus you have a much better seal, protecting the area under the amalgam fillings much better.
That mercury scare a few years ago that prompted so many to have the old fillings replaced was wonderful for dentists' bottom line.
But as for aesthetics, you're right. Amalgam fillings look pretty nasty compared to composite fillings.
I guess you haven't run across an "amalgamated" dentist who was "mad as a hatter" from mercury exposure, or, at least a bit strange.