First, I do like downbeat, apocalyptic fiction. I sometimes enjoy reading fiction that evokes anguish or that portrays failures. Kazuo Ishiguro is one of my favorite English language writers.
But... I didn't like "The Road" at all. I think I get the point, but to me it was essentially "apocalypse porn". It was about pointlessly and joylessly describing a dying, hopeless world, but in a way that wasn't interesting to read. I didn't even like how it was written, after a while I started counting how many times McCarthy saw fit to write "the last of [food]". "They ate the last of the biscuits". "They ate the last of the beans". Etc, etc.
I'm sorry but I cannot find better words for this, The Road felt like "hopelessness porn".
I expect people won't agree with me. So be it.