This is unfairly dismissive. The author recognizes Trello's success [0] and is sharing his thoughts. Is there something in particular he said that you disagree with?

[0]

Hindsight, of course, is 20/20. While I’ve spent most of this post talking about Trello’s missed opportunity, we shouldn’t forget that building a SaaS business that’s worth over $10M, let alone one that’s worth $425M, is a huge accomplishment.