Well in the link you pointed to, the author did it over a period of years. We'll assume he's drunk and it's only 1 year and a day. He seems to mention 6 default apps. That means he replaced 1 default app every ~2 months. That doesn't really indicate a bunch of time spent on it. It's just changes over a significant period accruing. Personally, I just don't give a shit enough to do that to my phone, but I do with Emacs.