Well you need 4 red sources by turn 4, which means playing at least 9 mountains (I would say). But you need white mana by turn 1, which means you need to play 9 plains. You also need to play a land every turn until turn 5 if you're going to run a crapton of 5-drops the way the RW deck above does. Almost a third of the spells are over 4 mana, which means you'll have a lot of dead draws. It just looks like one of those decks that, when the cards line up and you curve out, it's unstoppable, but if you don't hit your mana you blame your draws.
The BW deck, on the other hand, has 10 black sources, 9 white sources, 3 red sources, and a Pilgrim's Eye to get whatever color we need or help us hit a land drop. It also curves out, and has 6 removal spells, and a bunch of evasion too. (Yes, I'm counting the Evolving Wilds as a source of each color, but that's fine.)
I don't see where you're getting 4 red sources by turn 4, I presume you meant to say 2? The R/W deck also has access to the
Evolving Wilds so it can add 1 to each of it's basic land color counts. If you end up that hard up for white sources you can cut the
Mortuary Mire for another plains.
As for the funky curve you do have a point there, however with BFZ format the smaller ground creatures get outclassed too quickly.
Not saying W/R is necessarily right (I haven't played enough of this format to make that call), just that I don't think it's missing as much as you might think.
That being said, I really do love your B/W mana base, it's nuts.
Red also it's own share of evasion too: 2 menace creatures, 2 trample creatures, and 1 team trample creature. Admittedly not as good as flying, but still not vanilla.