>It appears my suspicion were correct.

The text in your post doesn't support this conclusion (which tradeoffs are causing the behavior?). Just because something isn't working right doesn't necessarily mean it is because of tradeoffs; it could just be a bug (Edit: that they aren't aware of).

Also, it seems strange that you are experiencing that problem since many pages have more likes (for example Barack Obama's page has over 35 million likes) and yet load quickly; perhaps the problem is unrelated to the number of likes?

Edit: Of course if it is a bug and Facebook is aware of it but hasn't fixed it yet then the reason for not fixing it yet may be due to tradeoffs.