What if you guess the starting difficulty and are wrong? Then you get no early adopters at all and your chain is completely stillborn. Expect 4 megahash, get 30 kilohash. Then six months until the first still vastly overinflated retarget.
Then maybe program more frequent retargets, at least it the earliest blocks. So you can indeed start at a difficulty that's way too low but fix that mistake before 100k coins are given away to 30 people between 3am and 3:10am. I'm not saying you need to aim for the exact hashrate, just don't pick anything ridiculously low like it happened in SC2.
Currency hopping is the new pool hopping. I find it funny that less than a day now separates "early adopters" from "late adopters" in many people's eyes.
When 2 months worth of coins get mined within the first day, this explains that, I guess... When you join a chain say a week after it launched, and mine nothing during a whole day because there's no pool and soloing is too hard (or you mine 2 coins in a pool), and then you see a few day0-day1 posts about the client glitching with 5-10k mined coins in it, you go "mkay, I'll just try something else".