But, it is an excuse. Because it's asking a question that is unanswerable. Just the fact that it introduces the thought into one's head makes it an excuse since it is entirely speculative and not based off of any fact.
Besides which, why is a 38 year old 6'9" D-man possibly being injured going to comfort anyone's thoughts on him being here in the future? That notion alone is insane.
I'm sure responses to this post will involve some rhetoric about "better than 90% of today's D-men", "premier shutdown defenseman", "off-year", etc. At some point, it is what it is. You can keep piling up excuse on top of excuse, but it's just reality at some point. And, in my opinion, that point has long since past and it's better that everyone (especially PC) come around to it.