The other thing is that without accurate navigation, MSA means nothing.
I bet it's a common mistake to carefully work out the MSA for some route, and then change the route. One might change it as a result of getting a transit through some bit of CAS.
If VMC, in England-type flat terrain, it should still be OK because one isn't knowingly going to fly into a hill. But in IMC....
Situational awareness comes into this heavily.