The people with this gene might sleep less but it doesn't really show what the long term health effects on the individuals are. 2 extra hours per day for life but dying 5 years earlier in your 80s might actually be a decent trade.
Perhaps our evolutionary ancestors who evolved in high latitude areas developed this trait given that those areas see much more sunlight (and thus longer days) in the summers. Conversely, I’m left wondering if their sleep patterns differ by season. I.e. they need less sleep in the summer, and dramatically more in the winter.