Speaker brands with rotting foams?

Every speaker that uses a foam surround instead of a rubber or paper surround is going to rot, period.
Refoaming kits are cheap and easy to use, and work well if done properly.

this isn't a brand issue, many/most brands have speakers that use foam surround drivers. It's a design choice.

Most of the speakers from the 80's and before had surrounds that could rot. Usually lasted 10 to 20 years and not a big deal to get repaired. There were some excellent and unique speakers from that era that were a bargain, compared to now. Granted, Mission 700's might not be worth the expense, but Infinity RS1b's ...

some of the foam one sees on modern drivers is made of rubber like fostex f200a

Wilson speakers used foam until the most recent models. Whoever has the older versions have to pay big money every few years. Even the foam on the cabinet front needs to be changed! Wilson should charge less for the maintenence.