Why do I need to sign up for a microblogging platform to use a completely unrelated calendar app???
Anyway, my comments about reducing friction aren't based on my own preferences, they're based on dozens of multivariate split tests I have conducted across many thousand unique visitors.
Every single time, forcing the user to sign up, login, enter their email or anything of the sort before getting to use the site SIGNIFICANTLY decreases engagement, time on site, conversions, and pretty much every other metric you should care about.