TechCrunch has 351k feed subscribers not 53,651. I remember when Mashable covered mainstream startups but, in face of competition, positioned itself towards a smaller niche (covering social networks). Today Mashable has close to 80k subscribers.
They had 53K at the time of writing ;) That article is from nearly a year ago..
I think that that is part of the key to understanding why the 53K are targetted- Because anything they're talking about now has a good chance of making it big later on.
It's a risk, and it doesn't always (seldom?) pays out, but if I were to infer into the minds ofany dozens of developers, I'd think they're looking at the Techcrunch readers as the type of Early Adopters that they want/need to get them started- The type of people who are going to get excited about a product, to tell their friends.
These are the people who will spend a day trying new technologies, whereas most "normal" people only try it once a friend recommends it.
Those targeting the TC-crowd want to find that friend.
It's not a matter of aiming small or finding a safe niche. Build something good and don't be afraid to aim big with broad appeal -- as long as focus isn't scattered. The market for early adoption may start off small, but that's frequently the case.
Consider HD TVs and displays. Years back, it was the enthusiasts who were the early adopters. But I can assure you HD is no niche market and the companies behind them were not aiming small.
There is nothing wrong with aiming small.