It reminds me of <https://xkcd.com/627/>, but when you're launching a product that isn't good enough.
It's hard enough to open up a port even with uPNP (typically disabled) and other made-for-purpose tech. Torrent clients end up trying to poke holes and such. Service discovery might work via local UDP broadcast, or it might not. LAN clients might live at 10.* or 192.* or be isolated by default. It's easier to just go onto the public internet and contact some mysterious server. Botnet by design.
