I guess there's some sort of furor over the Denver Broncos' quarterback because he's a religious fundamentalist of some variety. Or because he's not a very good quarterback in terms of the stock position skill set (ie, throwing a ball in the general direction of his teammates, or even human beings generally).
I'm not sure that there should be aside from one or two qualifiers. Here's what I would say
1) The success of most football teams is predicated on having a solid offensive and defensive line. Denver seems to have both of these in good standing. Quarterbacks merely exploit poor defensive lines/good offensive lines (by having more time to make a play). They deserve credit and attention, but not as much as they receive. Outsized credit and attention tends to come from the general charisma involved in playing the positions successfully. Tebow, for whatever his faults are, seems to be more or less charismatic in some way.
2) The second predictor of success would be whether a team plays a hard or easy schedule. There are in the NFL about 8 teams that are very good, potential title contenders, and then 4 or 5 good solid teams (Chicago would have been in the former group as a dark horse until their quarterback was injured, it's now in the latter. Detroit looks to be joining it soon perhaps). And the rest of the league is average or worse. Denver has played two very good teams and was demolished both times (Green Bay and Detroit). They did beat two solid teams (Jets and Bengals). So essentially Denver is 1 and 1 since Tebow began starting. Like in the NCAA I don't count wins against meaningless teams in the schedule. So. If they beat both New England and Chicago, count me as suitably impressed. Beating Chicago won't really impress me. Beating New England will. I expect them to lose by two touchdowns in that game. Even at home.
3) The one qualifier I would have is that he appears (by anecdotal evidence) to be in huddles with his religiosity at stake. God this and god that and so forth. I will admit such things are annoying. Even for the religious among us. Particularly given the amount of times there are huddles in football games. Chemistry is important to winning such games and annoying your teammates won't help that. That said, the real problem I would have with it as a teammate isn't so much the religion. It's that religion is not a substitute for strategy or play calling. So long as he calls plays sufficiently well, I would think a player would be fine with it. They seem to be doing okay as far as that goes. I'm not sure it's a sound long term strategy, but I'm not a football player. And football doesn't have very complicated strategic components nor operate with human lives at stake at least.
The reason I would worry is that this appears to be the level of strategic thought put into the Iraq War by Rumsfeld and some of the top generals. "Onward Christian soldiers" and so forth. As opposed to actually acknowledging difficulties and realities on the ground. I'd thought these were sentiments best left in the 15th century after the rise of the Ottoman Empire and the end of the Crusades. But apparently not.