I had heard once that being critical and contrary was characteristic of young men in their early 20s. Being a young man in my early 20s at the time, I immediately dismissed this as ill-informed and wrong.
Now that I'm a little older, I'm inclined to believe it. I could probably explain why this is, but I don't really have the space (or time).
Regardless, I've found that as I age, the energy I used to direct into complaining about others is best focused on improving myself and my work; and that the attention I used to devote to the frustrations I encountered were instead best directed to addressing the frustrations of those who use what it is I deliver.
I can't help but think it's a sign of growth. When you're doing your best work, the only time you're affected by the shortcomings of your environment is when you're working around them to solve the real problems. I'm done being frustrated.
Fine, you've aged some, but even my grandfather can find 30 minutes to complain about the styling or a car or acknowledge the collectibility of another.
I've graduated to discussing the collectability of pogs.