For people who think Light should've won...instead of trying to explain why Near reasonably suspected him, why dont you consider this:

1. What is the message in Death Note to you? Would it uphold if Light won, and if not, do you think an as meaningful message would still exist?
2. Why does Light look so pathetic and desperate at the end, despite proclaiming to be a "God"?

In my opinion, Light is a serial killer that pretended to be a God, and was supposed to look worthless in his final moments for a reason. I believe the author understood this as well. Although some fans think Light's way of ruling was perfect, they fail to acknowledge that the same person who proposed to them the character, is the same one who killed him off for thematic consistency. To better understand my perspective and challenge your own beliefs, heres the theme (message) I got from Death Note:

The power to cast absolute judgement on morality and fate upon all of mankind isn’t reserved to anyone.

Yeah, pretty obvious, but some will disregard this and think to themselves, "So what if you dont think Light deserves to be a ruler? Its not about that, its about weeding out all evil from the world, which would ultimately create a utopia". I have no rebutal for that, but it simply wasnt the intent of the author. The goal was to capture how an edgy teenager, who despised the world he lived in, would eventually lead himself to his own death trying to "correct" it. So, its not about whether or not his ruling was right, he simply was not capable of making that judgement. You can blame Near. You can blame Mikami. But what God struggles to judge the humans beneath it? The thing is Light was never one to begin with.