Government and Politics is absolutely fine. Yes it's not well respected but it's not 'soft' either. What matters more is the grade rather than the actual qualification itself.
One thing I noticed about facilitating subjects is that it's only mandatory to have them if you intend to do a degree in that subject, i.e. if you want to do a Maths degree, Maths is a must-have, if you want to do Geography, then the A Level in that is must-have, but if you want to do Politics or Psychology at uni, you won't necessarily need the A Level in that subject. That's really what facilitating subjects are good for.
There are subjects like RS/Philosophy, Economics and Computing that are considered on par with the facilitating subjects, but because you don't actually need the A level in that subject to do it at uni, it's not facilitating.
So no, your friend is wrong, I reckon you could still get into a good uni without ANY facilitating subjects except for maybe Oxbridge. While it's true that the facilitating subjects are well respected, a D in Physics is still worse than an A in Sociology for example, even if it required more work to get that grade in Physics.