Just some guesses - take 'em for what they're worth, and if anyone knows the real answers, drop 'em in:
WOF: The deluxe versions may have done well, but they were at a premium price, and they sold millions of the lower-priced versions, so why add the expense? Tyco/Mattel's version of the board design may have some proprietary rights.
One thing that may affect them all - I wonder if the prices of oil-based plastics are adding costs that companies are avoiding with more ink-on-paper props. That deluxe wheel was quite a piece of work.
A few friends of mine state they like a game where you just open the lid and go - no big set-up time. I bought a new game called The Perfect Ten and wanted to use it at a wedding party. The set-up time, large parts and tiny magnetic scoring strips made it unwieldy for crowd use - so we just invented a scoring system and used the questions. It's okay for 4 players, but, like MB Feud, there's set-up time involved, and some won't bother. I agree the Endless version leaves something to be desired. Perhaps a cardboard version of the MB plastic board that uses drop-in sheets, like Cardinal's Pyramid, could save time and money.
