Nobody said they were 'great' fans. I'm saying they're mostly normal fans.
Forget the corporate sections, you'll see the same thing just before and after half time in the concourses behind the standard seats in all four stands at White Hart Lane every week. Or how about the people who start leaving before the end whatever the score, so that they don't get caught in traffic?
From the comment about 'suites' I can only assume you don't know what the facilities are actually like.
If WHL had as large a proportion of 'prime' seating as Wembley does, it would be awful. On the whole, the people who sit in these areas contribute very little to the atmosphere and are much more likely than average to arrive late and leave early (at half-time and full-time). That's not to say they're not passionate fans, or that some 'normal' fans don't do the same thing, but there clearly is a difference.
I'm not a fan of New Wembley at all. Especially the ridiculously loud pop music they insist of pumping through the PA system, preventing supporters from making their own noise. I had a great time at the league cup final against Chelsea, but that was in spite of it being at Wembley, not because of it.