[DCoder]

There are good arguments for styling native elements and against them. I don't think this is specific to the web, cross-platform GUI toolkits have had this challenge forever.

The current datepickers on the desktop are "consistent in the same browser across many sites". There is no native solution for "consistent in the same site across browsers", which makes a lot of designers and PHBs upset, doesn't always fit the overall look of the site, and makes it harder for developers because each browser brings its own quirks with formatting, localization, validation, etc.