It all depends how they said it.
In my view it's fair enough though. Grand Central don't have any station/ground staff other than maybe two or three.The East Coast staff will have had other priorities such as dispatching other services etc. so why should they be taken away from that for another train company's benefit? The EC members of staff will be the ones taking the abuse, why shouldn't it be the GC staff? I'm not saying the abuse is right, merely pointing out it will happen and if it is going to be directed towards someone then it should be toward the right people! Why should East Coast get a bad rep for a Grand Central problem?
Or to look at it another way, why do we continue to accept a fragmented rail system, with in-built inefficiency, poor overall customer service and the inevitability of precisely this kind of situation? Time to re-invent a modern, integrated, customer focussed British Rail that all staff are proud to work for.