There's no EPG for most FTA singals because most FTA signals are not intended for home users to recieve. They're the primary feeds to the secondary providers who then rebroadcast the signal usually in a different format. The secondary providers then provide the EPG. That's why it's important to never contact the broadcasters of FTA signals asking for programming guides or anything else as we're generally not the intended audience (or at least not directly) and their reaction (like maybe encrypting the signal) to such request may not be good for FTA.
As for C band subscription based programming, it all began back in the days when there was no means other than cable to receive anything other than OTA tv. Back then most everything was unecrypted as FTA is today, but cable wasn't available in many areas. So, people began buying or building thier own C band systems to receive programming they could not receive any other way. Basically it was the same as FTA today as they were receiveing the primary signals straight from the networks without going through a secondary provider. Anyway, as C band grew in popularity the networks started to encrypt their singals but then saw a marketing potential and allowed C band users to subscribe to their signals. Anyway, even today when you subscribe to C band programming, for the most part, you actually receive the signal directly from the network. Of course nowadays there are a few exception to this. The exception are where networks no longer provide a primary signal that's compatible with analog C band or 4dtv equipment (like DCII Megapipe or DVB). Anyway, the basic principal of receiveing the signal directly is why on C band there's no programming guide from each individual network. It's also why all the signals are not available on a single satellite and instead the dish must move from satellite to satellite. The upside is that the first generation signals are usually of much higher quality and aren't overly compressed as they must be with the pizza dish services.
Nowadays cable is much more widely availble and there are now secondary satellite providers like Dish network and direct TV. So many networks no longer care about making their signal availble directly on C band as they figure most people will get it though a secondary provider. Therefore they often time switch to different formats that are unavailble to C band subscribers but are more convient and/or cost effective for them. That's why C band is dieing.