I don't like flying LCCs either (though I'll note this is only a two hour flight). I particularly don't like the much tighter pitch and all the add-ons. If you have *G benefits, that would be a further reason to fly SQ.

But end of the day, if you're primary goal is reducing cash outlay, use KF miles. If you want slightly better value per point, use AC. If you want overall lowest price, and are willing to sacrifice comfort on a two hour flight, fly Scoot.
The SQ flight I'm pretty sure costs more than the Scoot flight, so that calculation is apples and oranges. It's probably between 1.5 and 2 cpm for the SQ redemption, which is decent.