Why can't Roku TVs use the EPG instead of the Internet?

Just that. Roku TVs don't record shows like a DVR so why does Roku need a third party to provide the program guide through an Internet connection while every station broadcasting HDTV channels provides the EPG already? Using the internet for the program guide allows some third party to determine what you can and can't see on your TV by not providing channel information for some channels and subchannels. So I ask why? Roku needs to fix the issue (wasn't an issue until version 12.5.5 build 4174). So what did you do? Fix it.