Two reasons:
- Because a new person discovers Bad Voltage, thinks, “ooh I like this”, adds the feed to their podcatcher, and it downloads thirty episodes and they get cross with us (you may think: that’s their podcatcher’s fault, and you’d be right, but I’d rather be wrong and helpful than smugly right and irritate our listeners)
- There seems to be no way to tell podpress to create a feed with all the episodes in it; the “max amount of posts per feed” setting is ignored. See Bad Voltage for iOS for previous discussion on this point.