"People seem to use this as a proof text that people dont have an excuse for knowing God (although I argue it doesnt say anything about not having an excuse for not knowing the means of salvation), so what are your thoughts?"
Whenever the subject comes up of what happens to the African who never heard the Gospel, the above scripture is usually the one quoted to justify the fact that billions of souls will be tortured forever. This is usually the only scripture quoted to justify God. Taken out of context and put into the discussion of justifying God's behavior, this seems like a reasonable Scripture to quote. But when we put the Scripture back into its context in the entire book of Romans, and put those words into the apostle's mouth who never preached a hell of eternal torment in this or any other book he wrote, we then discover that this passage has nothing to do with the subject of the African who never heard of the Gospel. If you don't believe Paul never preached hell, look into the Strong's Concordance and look up the word "hell." You will discover it is mysteriously absent from Paul's vocabulary. The apostle to the world seems to be preaching a different deliverance than the modern church is preaching. Paul wrote that if anyone preached another gospel other than his, let him be accursed. Paul never preached "hell." Where does that put the "modern gospel?"
It should be obvious to anyone who will study this passage, that if one concludes that it is possible to "get saved" by looking at creation and discovering there must be a God, then Jesus died needlessly, the Gospel would serve no purpose, and there is another way of salvation other than the Gospel. Most of the world believes there is a god based upon looking at creation. Does that save them? Is a Moslem saved because they believe in a god? Was the Roman pagan even more saved because he believed in several gods? Since when does looking at a cloud bring one to "Christ crucified?" And if looking at creation, and determining there is a god can bring righteousness, how does that line up with many other passages from Paul that clearly declare, "There is none righteous, nay, not one." That includes those under the law (Jews) and those not under the law (all the rest of us).
Please observe that the list in verse 29 through 31 refers to people here on earth, not in hell and the penalty is death, not "eternal punishment." Putting this Scripture back into its proper context, we find it connected to a "therefore." This "therefore" connects what was previously discussed. "Therefore you are inexcusable, O man, whoever you are who judge, for in whatever you judge another you condemn yourself; for you who judge practice the same things. (Romans 2:1) Now that turns the tide a bit. The very person who places these people in "hell" and says they are without excuse is actually condemning people, judging people while they practice the very same thing! - Gary Amirault