Meetup's blog on the redesign.
Digital Trends: take on
Richard Boenigk, Principal Designer, your site looks childlike now and it is harder to find events.
Techcrunch:
“We killed the calendar,” CEO and co-founder Scott Heiferman said. Instead, Meetup will recommend listings for you based on your own interests
Reminder, the calendar helped people keep track of their upcoming events, so that they could ensure they would be able to attend.