I just had a look on Tripadvisor and I have to say that I have never seen an IHG hotel with such a low score and with a GM with such an attitude, it really doesn't read well at all.
Sure, it's fine to have a different point of view, but the way he comes across is very unprofessional and arrogant, it wouldn't exactly encourage me to bring up a problem I had with my stay there.
Bet you they don't have "Is your stay a 10/10" card there!