Bill Maher's raison d'etre is to say things that piss people off. He's done that.
My issue with Tebow's displays has nothing to do with him personally - what little I know of him is that he appears to be a grounded, compassionate person who volunteers his time and money to causes that he feels strongly for & has a strong Christian faith. All fine things, IMO.
My issues here are twofold: firstly, Maher (and a large number of other atheists) do the very thing they (not unfairly) accuse most religious folks of doing, which is to refuse to accept that you came by your way of thinking on your own, the same as they did. If I choose to believe there is a magical, ancient, purple dragon who lives under the sea & grants my wishes if I stand on my head & chant "Ipsy, dipsy, tinky goo, fluffernutter bramblescratch dew", then it is my inherent right to do so. It is not your right, your place, or your mission to tell me otherwise. If I'm wrong, I'll have to face those consequences at some time, same as you.
Secondly, I've never been a fan of religious show boating. I have my own faith & while not ashamed of it, I don't believe it's something I need to wear on my sleeve for the world to see. I offer prayers on a regular basis (prayers for thanks, prayers for healing, prayers for wisdom or patience to deal with a difficult situation, etc.) but I don't make them a spectator sport - I wait for a private moment. I don't use every conversation to browbeat people about my belief system. And though I don't personally engage in the activity on my own, I don't oppose my mother's or in-law's tendency to offer thanks in a restaurant where others will see us because they do it quietly & discreetly (as part of their normal pre-meal ritual), not to provide a showing of how devout they are.
My belief for some time has been that if you have to constantly tell people what a good person you are, maybe you're not actually so great. My actions and words will tell far more about me in the end than whether I carried a Bible everywhere I went and called out God's name for various achievements throughout my day.