Why? Different tracks have different grip levels. Low is not necessarily bad, the same as having eco tyres on your car is not necessarily bad. It's just different.
And the Alps was their new fantasy track to the series, and showed off the improved graphical capabilities of FM4. It was a natural choice for the demo track. I mean, what else would you choose?
It's also a fairly good track as far as getting a feel for physics too. Fairly flowing, plenty of elevation change, nice mix of high and medium speed corners, not too complicated to find your way around. It's a nice track in anything but the slowest cars, once you adapt to the fact that you really, really need to let your tyres warm up before you go ten tenths, and even then it's greasy.
Then again, keeping an eye on your tyre temperatures isn't really news to anyone serious about simulation racing, or even racing in general.