Earlier quoted context omitted.
If it's public facing, that's a huge concern. If it's intended for business users, particularly if on an intranet site, it's often very easy to limit the number of browsers and versions you need to support to just a handful.
The Web has been collecting dates from users in forms long before date-pickers existed.
Re: A single-page app is almost always worse than a multi-page app
#151The Web has been doing lots of things poorly for a long time as well. I know I've seen some implementations of date-pickers I don't like, and more old school implementations without date pickers that were just clumsy.