If he's that kinda guy, & i mean it the nicest way, he needs to swallow his pride or park his ego, if he's going to survive & prosper, the fact that he's previously asked you to Marshall for him shows an element of trust, maybe its worth having another go at constructive critique, if not in person then a call or maybe even an email, explaining where you think he's gone wrong with the layout & how he could gradually improve it, maybe by recycling or reconfiguring some of his structures that have negatively affected the games ebb & flow.
Don't get me wrong, don't know the guy, nor have I played his sites, but like you I've played lots of other sites, some great & some dreadful, & sometimes the bad ones have enormous potential but are badly run, crap staff, shite game scenarios, or alternatively amazing enthusiastic staff but the site layout/size/location makes decent play untenable.
But none of us want to see a sites demise, we've lost too many already to development etc😢, especially cqb themed.