Not sure how thats relevant really, a TT is an A3 based entry level sports coupe so of course it has the same interior level.
Well no it doesn't, but again, if it did, the C Class isn't an £40k base car either is it - it's Mercs lower end volume saloon.
Look at a car that starts at £40k and you'll notice it's somewhat better made than one that starts at half that but can be optioned up to £40k with powerful 4 pot engines, stick on spoilers and a Haldex system
Of course loads of people don't care and these people will happily buy these cars, but I'm just explaining why some people think £40k is simply too much money to spend on a hatchback.