No it wouldn't be fair, but at the same time, Obi-Wan still felt as though he was responsible. Despite the fact that whatever happens, it's 20 some years in his future. Perhaps that was irrational thinking, but just the same.

"Even the best intentions can have unforeseen circumstances. I can't justify my actions in the future, but it is clear that they have caused you pain. For that, I am sorry."

It might not mean much coming from him, since he didn't know the circumstances. But the gesture was sincere.