Objectively speaking, the results of building a team around a PG, much less a 'pass first' PG, have not been strong from a championship perspective.
Those on Csblog who choose to eschew that reality tend to be Rondo fans that just don't want to hear it.
The people on celticsblog who push that reality tend to be people who don't understand that title teams are built around transcendent players and it's silly to draw any other conclusions from the roster. Sure, you don't need any particular kind of point guard if you have LeBron or Shaq or Duncan, but if you don't have a LeBron or Shaq or Duncan then your team's equally unlikely to win a title whether you build around a point guard or wing or big.
Would you call Rondo a "transcendent" player? How many PGs in the league would you consider transcendent? Following your definition, why have there been far less transcendent point guards than big men in this league, when there are always far less men with "NBA big" size on this planet?
It depends on your definition of transcendent. I've been talking about players like Larry, Magic, MJ, Shaq, Hakeem, Duncan, LeBron, Isiah and Kobe. He's not on that level, although he's probably capable of playing close to the level of the lesser players in that group (Kobe or Isiah) in the playoffs when he's healthy. He's not a "make your team favorites to win the title" player, more like a "give your team a shot at a title" player. Obviously I'd rather build a team around any of those players than Rondo.
If you want to know why there are more transcendent big men than point guards, it's simple math. You're comparing all the players at two positions to all the players at 1 position. Are there more transcendent bigs than transcendent guards? Probably not. Are there more transcendent bigs than transcendent wings? Doubtful. Are there more transcendent players at any 2 positions than any single position? Yes.
As for the fact that there are fewer tall players than smaller players? The nba is somewhat height based, meaning that the taller you are, the bigger your impact for a given skill level. If Bradley and Vitor are equally skilled players then Vitor will have more of an impact on a game. If Rondo was the exact player he is but the size of a center he'd be the best player in the history of the game.
However, there's never been a center in the history of the game that could handle the ball, pass, or move like Rondo. Many centers have had more of an impact on the game than Rajon in spite of that because their size compensates for their lesser skills. This is why, btw, many people (including myself) consider players like Bird and Magic to be so special. They had tremendous skill levels for their size, the best I've ever seen.