I'm also 31, and I don't think this article is talking about us. I think it's talking about people who are 15-20 years older than us.
I do agree that I am way more experienced, knowledgeable, and have a much more healthy and mature perspective on business and software engineering than I did when I was 22.
It is talking about people with kids and such - you know, 30-40. Basically, you, very shortly, if not already. The article specifically called out people with kids, and pointed out that at the age of 30+ VC starts being skeptical of the chances of backing the founder.
You are a year or two from being 'old' in this mad market.
I do agree that I am way more experienced, knowledgeable, and have a much more healthy and mature perspective on business and software engineering than I did when I was 22.