1) It's made by Apple. If the Tivo had been made by Apple it would have sold vastly better.
2) You can carry it around with you, and let people play with it in public. When the iPhone first came out every time someone got theirs out they were surrounded by people wanting to have a play. Tricky to do that with something that's plugged in under your TV.
Also note that Apple entered the smartphone market after securing a deal from AT&T to subsidize the cost of the phone. That was their execution strategy and it delivered.
But they completely flopped here in the UK, where the culture of cable/dish TV was much lower. And that was down purely to not getting their message out.
It really wasn't that long ago that Apple was the pariah of the technology world. iPod might be a better comparison. At the time they introduced iPod, the people buying Apple products because it was Apple was a small, rabid cult following, not a sizable part of the general public.
Personally, when they decided to lock up the system (predating GPL3) I put the company in the AVOID column : not a good step for a tech company to alienate potential enthusiasts.