Nearly every major WordPress theme provider offers the ability to easily add Google Analytics or other tracking code via the theme’s options panel.

I'd at least think the major providers wouldn't do this. I like to consider myself in that pool of theme providers, and it's something I definitely don't do.

@Devtard

I actually prefer to hardcode similar things into the theme – I try to avoid unnecessary plugins whenever I can.

I'm not sure how that makes it an unnecessary plugin. It literally takes the exact same amount of code to add it via plugin as it does via theme. This is precisely the reason the plugin API was created for WordPress.

Not to mention, whenever you change themes, you've got to remember to copy and paste that code into your new theme.