Earlier quoted context omitted.
Because it's obvious. Business model 2 involves significant capital expenditure. Business model 1 involves the same profit without the risk; all they have to do is cut deals and act as rent-seekers on their existing infrastructure. They'd have to be fools to go for model 2.
You're not thinking it clearly. As long as you assume them to be profit seeking individuals and not some inconsistent model, then their choice leans far too heavily towards investing in their own infrastructure (even if you assume a bully who is ripping people's lunch money to invest some of that lunch money into a gym membership). If they launch Verizon Music, then they'll have to build a service as good as Spotify…
Not really, they could just charge an additional $10/mo for users to access Spotify and people will start to choose Verizon Music since it is half the price, even though it is worse, which then bleeds Spotify dry.