I can deny it rather handily. It retained its theme of obsolescence very strongly, all the way through to last two missions. Unless you played really fast, it took me a lot longer than five hours to reach that point.
Also, I find it a bit amusing that a ruthless Serbian soldier becoming a killing machine has no basis in logic. The city and his own lack of experience in it pushed him to the things he did. I never found myself turning to avoid any kind of mission-based conflict for Niko, in stark contrast to my complete inability to go on any rampage whatsoever. The story, I felt, gave him adequate motivation for everything. Financially speaking, he was helping his cousin, but also I'm sure he wanted to cement a life for himself. I don't think it's a fault of the storytelling, but the money system of the game definitely worked against this.