True, there are typically enough points on the board for you to take care of it slowly on Normal if you want. It's just that I noticed today that the time multiplier is multiplied
after you add up the difficulty and skull multipliers, so it's a big bonus. You can double or triple your score by using that.
e.g. - I was using Tough Luck, Famine, Fog, and Thunderstorm + Heroic, which is a total of 8.5x. When you use my time bonus of 2.0x, it makes the multiplier 17.0x rather than 10.5x.
Click for example.
But as you said, there are plenty of different ways to get it done.