Driving customers away

I have a frequent flyer account with Virgin America. They want me to sign up for some new thing, and they’ve sent me two emails about it so far, with lots of good call-to-action language, and a big “Join Now” button.
But this is the start of the form that clicking on that button leads to:

(It goes on further, finally ending up with a captcha and a submit button.)
Virgin America already has all that information, and it’s all tied to the account they sent the email to. If they were to have pre-filled the form with that personal information I might have looked at it further. Quite apart from the annoyance of having to give information that they already know, I’ve no idea what my frequent flyer number is and I’d need to go and look it up before I could go any further. From a typical recipients point of view this makes it much less likely that I’d consider signing up for it. That barrier to entry drives people away.
From an email/privacy professionals point of view I know why they do it this way, though. This web form isn’t Virgin America’s form – it’s a third party that Virgin America is doing co-registration with (though neither party is as clear about that fact as they could be, of course). Virgin America are being paid by that third party for each new sign up they capture – but they don’t want to share their customers private information with the untrusted third party. Doing the information capture this way, by just using their mailing list to drive traffic to the third party’s website is very cheap to do, much cheaper (and so more profitable) than doing it “properly” by having Virgin America induct people into the third party program, and reducing the barrier to entry to just a simple disclosure and “Sign me up!” button.
But treating third-party co-registration signups as “free money for almost no investment” only works if you don’t consider the attention of your existing customers valuable. Of the past five emails I’ve received from Virgin America, only one has been talking about buying flights – the other four were, like this one, co-registration offers (credit card, car hire, vacation, online surveys), with varying degrees of Virgin branding. They don’t really bring much benefit to recipients, and they’re a bit intrusive.
I’m not sure how much Virgin America is paid for dropping this sort of co-reg and third-party advertising into their mail stream, but it can’t be that much (does anyone know?). Treating your existing customers as a resource of cheap, fungible eyeballs to be sold to random third parties, rather than as people you’re maintaining a relationship with, risks driving them away from your email program. Given the value of a loyal airline traveller that can’t be profitable in the longer term, and likely not the short term.