Two week notice during the holiday season seems pretty sudden and painful for users. I feel bad for those who now have to scramble and probably miss time with their families as a result.
In my eyes it's evidence that you definitely shouldn't bet your company on a startup unless you have a backup plan that you can implement quickly or the benefits are massive (ie: the reward is worth potentially losing your business). Larger companies also kill products but they tend to give a lot more heads up.
Customers have options, scramble or not. My sympathy is with the staff, sorry "teammates" (per the webpage). It's a lousy time of year to be out of work.
I'm willing to bet the team worked with customers ahead of the announcement in good faith. Hacker News threads aren't always looking behind the curtain at what's really going on.
I really feel bad for those who committed their company to this company.