Yeah I'm pretty sure this is just the case of an overworked unpaid tech support staffer saying something very wrong. He probably meant that the compatibility modes offered in Windows 7 are not officially supported regardless of whether or not they may solve the user's problems.
According to everything else- the game is officially supported on Windows 7. So one can believe that all these statements (from the official requirements to being a "Game for Windows") are either all mistakes or a concerted and conspiratorial effort to deceive the customers - or one can believe that a tech support staffer made a mistake.
I would tend to apply Hanlon's Razor:
Never attribute to malice that which is adequately explained by stupidity.
and Occam's Razor and presume a single mistake rather than a series of the same mistake being made by dozens upon dozens of people for months or a conspiracy. Still it's a pretty upsetting mistake to be on the receiving end of when you're trying to get help with your game.
As far as their Better Business Bureau ratings go- they don't really mean much as Zenimax is not accredited and not an active participant in the Better Business Beureau. This does have an inherent effect on their score as one of the explanations of the score given is "BBB does not have sufficient background information on this business." In addition to not having enough information about them- their "F" comes from 19 complains over 36 months - only three of which were not marked by the BBB as resolved. If you browse accredited (whom would have provided plenty of information during the accreditation process) companies you will notice that this scale and response ratio will normally garner anywhere from an B to an A. Also, Zenimax is the parent company of:
id Software
Bethesda Softworks
Vir2L Studios
Mud Duck Productions
ZeniMax Online Studios
Arkane Studios
Tango Gameworks
Machinegames
So how fairly those 3 unresolved complaints can be divided up amongst the subsidiaries is arguable. It may be important to note that the listing under which it receives an F is as under "Computers - Dealers" and these complaints may be unrelated to their software products but from the sale of old computer equipment. Were one to file a complaint for Zenimax under "Computer Software Publishers & Developers" then this would create an entry for that company under that existing business category. When these complaints were filed, they were filed with the complainants selecting the description for hardware resellers. I can understand a couple people selecting the category for hardware resellers by mistake- but the fact that only one complaint was filed under anything remotely related to gaming and none under software developers makes me thing it is strongly possible that those complaints weren't related to their software.
Don't get me wrong though- I'm not suggesting they should have any particular rating. I just don't think you should trust a rating system where membership is effectively 1/3 of the scoring criteria since it is the only reliable way for a business to "provide sufficient information." Inquiries placed to their phone and email system regarding how to provide them with what they consider "sufficient information" will be routed to explanations on how to start the accredidation process. Part of what constitutes sufficient information is also, hilariously enough, providing enough information to convince them that you are abiding by the standards under which you were accredited.