Yes you raise a good point - and especially in light of what Ezekiel 18 teaches. The idea of inherited sin contradicts Ezekiel 18, where the point is made that each one will answer for his own sin and mentions that a son will not have to pay for the sins of his father!
Here's another important point often missed: When arguing against hellfire, JWs sometimes ask the person: "Do you think it would be fair for God to not warn Adam that he would go to a place of torment when he died, if he ate the fruit? Surely God would have warned him about hell if it existed!"
Well, similarly, how could it be fair for God not to have warned Adam, before he sinned, that his disobedience would result, not only in his own death, but the death and suffering of countless generations of his offspring! Adam and Eve thought that they would die soon after eating the fruit. They were kept in the dark about the pain and suffering their actions would bring to billions of people, until after they had sinned.
And here's another point which exposes the dishonesty of Romans 5:18,19: If everyone is automatically condemned to death for Adam's sin, even without having to exercise faith in Adam or do any special works, then shouldn't everyone automatically be justified for life by Jesus' death, even without having to exercise faith in Jesus or do any special works? The undeserved kindness through Jesus is clearly not greater than the condemnation through Adam.
Here's some other interesting questions:
Is it a sin to just have sinful desires without acting on them?
If it is a sin, then how can a perfect being prevent himself from starting a sinful desire when its impossible to prevent a desire from coming into your heart without having to first think about it? How does a perfect angel startto have sinful thoughts, if he's perfect?
Also if sinful desires are a sin, then how is it that James 1:14,15 indicate that desire gives birth to sin, thus indicating that the desire itself cannot be a sin?
If it is not a sin, then doesn't that contradict what Jesus said at Matthew 5:28 and Mark 7:21-23?
On a lighter side: How could Jesus provide a corresponding Ransom when he wasn't fully equivalent to Adam? Jesus had some skin removed from down there, which technically makes him less the man than Adam was and therefore not a perfectly corresponding ransom.