I don't think the GP was implying a purely random process, rather the fact that if there are 20,000 games submitted for the bundle, your chances of getting picked are pretty low (akin to a lottery). As an indie dev, you have some knobs in your control (how good you make the game), but many knobs won't be.
There are a lot of really good indie games out there, but most people are only aware of the famous ones, or the ones they get exposed to via stuff like the HIB or high-visibility steam sales.
If you enjoyed the HIB games I suggest you keep digging as there are many, many games out there at the same level as the average of the game in the 4 bundles.
