What is wrong with you people, well if you forget let me start this off by saying "NOBITO almost lost to konan, she pushed him to his limits forcing him to use Izangi in order to win." So if your going to say that Obito beats Hashirama then you must also say that Konan beats Hashirama.
Now lets move one a little bit.
1) Obito has very little offensive capabilities that are not close range. This is not counting summoning tailed beasts/Jinchuriki, which wouldnt pose much trouble to Hashirama anyways since he can tame them with his 1000 years of bliss jutsu.
2) As Obito is close range he is only playing into Hashirama's hands, Hashirama is a close range specialist, he wields up to 9 different weapons at once controlling 1 himself and the others with wood. On top of that he has Wood Style which is dangerous close range as well.
3) Lets not forget Obito's weakness which is that he can only stay intangible for 5minutes, after that he can no longer do it. This is important because as soon as he gets too close to Hashirama, Hashirama can back him off with Wood Style, and lets not forget that Hashirama can heal himself without forming seals which is going to make it hard to deal permanant damage to him.
4) Last but not least Hashirama has "Eternal Darkness Jutsu" which is a Genjutsu specifically designed to blind Sharingan users.
I dont understand how one can claim that Obito can simply defeat Hashirama. Wait im not finished yet, one more thing.
1) Obito was upset/surprised when Kabuto summoned Madara to the battle feild. It is obvious that Obito planned on making himself the Jinchuriki and Madara being there gets in his way. So the question is if Obito can solo Hashirama, and Hashirama defeated Madara, then why wouldnt Obito simply defeat Madara? One can argue that The Shinobi Alliance was there, but they would have no reason to step in, they too would want to wait for one of them to defeat the other.
So we see that if Obito was as confident in himself as you guys are then he would have killed Madara, the same Madara who took on the 5 Kages and the Shinobi alliance without breaking a sweat... the Same Obito who could barely Naruto, Kakashi, and Gai.
Stop all this non-sense, Dont overrate Obito.