> I equate it to partnering with AT&T on the first iPhone.

In terms of strategy, they picked the underdog carrier (Cingular) specifically to avoid having to bundle bloatware and carrier customization at the cost of exclusivity. Likewise, when Apple brought the iPhone to Japan, they did the same thing with the underdog carrier here, SoftBank.

The strategic importance of this was as a bargaining chip with other carriers and fundamentally gave them a lot of control they would not have had if they had gone with Verizon or similar.