Why is support for fsockopen() in PHP fading among webhost companies?

Without sockets, users of PayPal's IPN cannot postback the verification to IPN, meaning anyone using Yahoo Webhosting (and any other host now not enabling sockets) cannot use that webhost and has to switch to another webhost. After all, they aren't going to switch away from PayPal IPN, it's the only game in town.

Anyone have a workaround for fsockopen() in PHP?