It's not what Adobe would prefer, but what Facebook wants. As regards the latter, Facebook is an advertising funded business from which they make a lot of money. See: Facebook Could Surpass $1 Billion in Revenue This Year
Companies which advertise on Facebook want; in fact demand that the products they want to display in Flash meet their expectations. Since Adobe also makes their money from selling licences for commercial use, they're keen to meet those expectations in order to ensure that businesses don't switch to another technology.
So I'm afraid to say that unless your system meets the Minimum System Requirements to display all those ads, then you're going to be left out in the cold.
Hummmm.... I sent you a message because I couldn't get this page onboard. The person above is right. Adobe is not supporting any pre-Intell Macs. Adobe offers no help, but here is an unsupported link that worked for me and could get you back onboard. If you follow the instructions to the t, which includes deleting space, you should be able to "see" again. Good luck, Julie R