My time is more valuable than manually managing servers. It's an incredibly basic tradeoff: some people are more price-sensitive, others are more time-sensitive.
In my case, if I end up working on an app that reaches the scale where Heroku isn't appropriate (for cost or 'omg I need metal' reasons) again, I'm sure there will be someone else on my team who lives and breathes ops. I can manage, but I'd rather be doing almost anything else.
(and when I tried to load the article, none of the body text loaded, I had to refresh the page...)