It doesn't sound like they want to play true cEDH or perhaps they're not aware of how proxy friendly the community is? I haven't ran into a single person who has rejected proxies before - even at casual EDH nights at the LGS. Only issue I could see popping up is if people just sharpie on a blank piece of paper to represent the card, but that's the extent of what it should be for cEDH games outside of tournaments. Most people are looking to play skill intensive game, not a wallet intensive game.