Legacies have set themselves up a comfortable business model where they do not have to care about their customers. VX threatens that and when someone cannot control a situation, they get angry (hate).

Many pax feel loyal towards a particular airline (sometimes via fear they will lose points/status if it dies) and take the threat personally. Instead of hating VX, they should be pushing 'their' airline to offer the same level of service, but most ppl will unfortunately realize that fight is a futile one (how about more executive bonuses instead).

Virgin products are (usually) aimed at giving customers a better deal in markets where they are getting ripped off.

Just my opinion/take on it, you do not have to agree.