Women? There ain't no womenfolk here.

Ataccounting wrote:
It's probably in their contracts. Somewhere along the way they got more money in return for the rights to their voices being used in Simspons related products without additional payment. The "minor" voices probably have to be paid specifically for their voices to appear. (Guess based on experience in other places)

Thanks for the explanation. That makes sense. Bummer tough because its a lose-lose situation. The voice actor will never (rarely) get any additional money anyway because producers of related products won't use the voices if they have to pay for them, and we will miss out on some great voices.