1) no one is actually implementing these changes; this is just a design exercise from someone who has no connection or influence with Github other than I presume being someone who uses it. My reading of this design work up is that it was just a fun exercise for someone with design skills; design kata if you will.
2) as a programmer who has occasionally tried my hand at a little bit of design; to my mind the design process is somewhere between fricking hard and near impossible and I appreciated the article taking me through his thinking and the incremental changes along the way. I may not like or agree with all of his choices but I really liked the insight into the process.
Obviously it's fine to not like the final design he ended up with, but given the above context I think the level of harrumphing discontent of some comments is not really warranted.