I feel your pain but ultimately you can argue fairly convincingly that you are paying for the transportation and actual service and that the "hard product" is a by-product. In fairness to Virgin, they aren't the only airline with such a differing hard product. Some airlines have a vastly different offering.... just look at Delta's widebody fleet and even across the Emirates fleet in certain classes.
Virgin are actually quite savvy in that they place the better hard product on the LHR routes which are probably more profitable with high premium demand whilst ex LGW is mainly leisure and demand swings more towards the rear cabin.
Overall though, Virgin are often viewed as the holy grail.....usually by joe public these days, but they really aren't as innovative as they once were. They aren't a bad airline at all but some do expect more than what they actually get and can be dissapointed. I'm not at all saying that you were one of these people.
You mentioned the crew.........FYI, LGW crew are dual based and so operate LGW and LHR.