The other Uchiha's maybe were just too focused on war, the will to win it and didn't really give a crap about emotions and feelings and stuff, evidenced by Madara's father not giving a bit amount of poop about his son being killed...he didn't get mangekyou when he saw his son's dead body so i'm right...right?

And Itachi dying infront of sasuke yet he didn't awaken it, that was at the time when Sasuke hated itachi....but only after he learned the truth about itachi he got it..

You could be right. It's also possible other Uchiha got it, but there was no record of it (sort of like how the Rinnegan was considered just a legend by some because until Madara and Pain, no one in modern times had it). I can imagine a Uchiha getting it during battle to avenge a comrade, then dying from wounds, leaving no one alive to testify about it.

Dude, Tajima was willing to kill young Tobirama just to get an edge in battle...clearly he didn't care about emotions, which a requirement you need to awaken it. Apply the same to Uchiha who didn't awaken it.-

I'm not sure, you could be right. Look on chapter 624: it was said that if their children got attacked, the father's of Madara and Hashi would be emotionally vulnerable, so seems they did care for their sons, but...it also implied that it would unbalance their hearts slightly. So I guess your right.

So maybe it's their attitude and personality that matters. The ninjas back than probably still believed in killing their own emotions, to a certain extent.

It was discovered, Madara and Izuna were more a rediscovery. Going strictly with the manga, Indra could use Susanoo, meaning he had MS. If you want to get really technical, Itachi said Madara and Izuna were the first Uchiha to have MS. Indra wasn't an Uchiha, he was an Otsutsuki from whom the Uchiha descend. The wording also leaves open the possibility of other pre-Uchiha Indra descendants to have awakened it (we don't know when the name Uchiha actually came around), the knowledge of it simply being lost through generations (no doubt many clansmen getting killed contributed) until Madara and Izuna awakened it again.

Just adding to Omnibender's response: we also know that there were several other Indra's reincarnations before Madara, and while we cannot be sure that they all possessed MS, it's more than possible.

Do you know chapter it showed Indra using Susanoo?

Chapter 670.

Same chapter it shows Aura with a rather odd looking Kyubbi cloak of some kind. Really wish that would be explained.

Most Uchiha died before their 20s during the warring states and most of them were cold hearted bastards who lacked the emotional capacity needed to unlock it.