I don't agree with this - because in all honesty, SendGrid probably should have had some sort of contingency plan setup to handle extremely high amounts of traf

I don't agree with this - because in all honesty, SendGrid probably should have had some sort of contingency plan setup to handle extremely high amounts of traffic. Sure, the public facing website may have gone down, but the API & other servers should have been able to scale up or down depending on load. When your service is as relied upon as an email provider, it needs to have near perfect uptime in order to keep trust. People were tweeting @SendGrid wondering why it was down for hours, and were looking for other providers to pick up anyway.