Agree with ChippyChop. There are all kinds of situations which may not allow for a safe landing. And two engines doesn't mean there is no single point of failure.
Personally, I wouldn't fly an extended period of time over a solid layer without anything sticking out of it. But there are also situations in which it is actually the better choice to fly on top in nice weather rather than underflying it in the ****. I've been flying once from Santa Catalina island back to Torrance and there was a layer of cloud at 1500ft which was, lets say, 7.9/8. So from time to time, you could peak through holes in the layer and that also told you it wasn't that thick. I am sure scud-running under that layer would have been the worse option, also considering that there are some hills on the coastline going up to 1200ft . So I think teaching dogmatically to always avoid VMC on top is not the right thing.