Heroes survive worse hits all the time in comics...
When a Mindless One killed himself with the Ultimate Nullifier, Spider-Man was leaping to save him... he was more than well within the blast's range... and guess what, he was only bleeding from a finger afterwards
Thanos is an uber threat only under Starlin. With so many heroes present and caught by surprise, it's no wonder he got taken down.
It's pretty hilarious that Bendis has She Hulk saying 'Weird sentence structure' or whatever, as he's the only person who writes Thanos as talking like that. There really are some characters he just doesn't know how to write (another is taskmaster, who he writes like a 19th century gentleman).
As for the fight Thanos wins, I mean a) he's against far more than just BM and BP in that awful Bendis fight and b) I don't think he ever used one of his own energy attacks there, which would almost certainly be better than the guns he's inexplicably packing.
Thanos used to be really awesome and now it's like he has Darkseid syndrome.
__________________ Chicken Boo, what's the matter with you? You don't act like the other chickens do. You wear a disguise to look like human guys, but you're not a man you're a Chicken Boo.
Well let us be fair, Thanos is a Darkseid rip off. So he should have to pay his dues like Darkseid did. Which means a period of time where he is pitiful.
__________________ Chicken Boo, what's the matter with you? You don't act like the other chickens do. You wear a disguise to look like human guys, but you're not a man you're a Chicken Boo.