This pretty much falls in line with my way of thinking, too. Weird things in games don't generally frustrate me much if I can understand where the developer was coming from when they made the decision to set something up a certain way. In the case of a game like Splatoon, from a developer like Nintendo, it generally feels unlikely that things like mid-match loadout selections were just overlooked "common features." On some facets of the game when compared to others in the shooter genre, perhaps, but regardless of other games this is Nintendo's first in-house online multiplayer shooter, so I don't entirely expect them to follow suit with their contemporaries' checklists.
Not so much "why isn't Splatoon F2P?" as much as he mentioned that TF2 is a F2P team shooter (they were trying to draw parallels between these two but I'm not sure how strong any of the connection really is), and discussing how TF2 has nine widely-varied classes, while the Testfire only had 4 "classes" and Nintendo expects 60 bucks for it. It was a bizarre analogy and probably one you could apply to pretty much any multiplayer game if you really wanted to. Mostly I think it was a jab at how it sounds like Splatoon will be content-and-feature-lite at launch, again, compared to other standard shooters.