Then why can't they plug in Power, TV & phone line? That's where IPTV STBs are going...
OK, I can see that you could use such a set-top box to sell broadband to households which would not otherwise buy Internet services. But that is a niche market.
Especially as more and more ISPs/telcos hand out WLAN boxen of various kinds - after all, once you have some sort of Linux (usually) networked appliance in the user's premises, it's quite simple to deploy more services (hosted VoIP, IPTV, media centre, connected storage, maybe SIP/Asterisk..) on top of that.
He didn't say that his STB had an Ethernet port. And I'm not aware of any generic Linux box that can be used to deploy additional services other than do-it-yourself. And that too is a niche market. Also, note that the proliferation of boxes, each needing its own power connection and some place to sit, is causing its own problems in the household. Stacking boxes is not straightforward because some have air vents on top and others are not flat on top. The TV people have not learned the lessons of that the hi-fi component people learned back in the 1960s. --Michael Dillon