That gives the sentence a new meaning, and the meaning you were going for. Since the second half of the statement is now a dependent clause, the reader knows that it's essential to the meaning of the independent clause, or the first half of your statement, something that was missing from your original post.I'm actually kinda surprised he's been a pacer for this long, and that this is surprising.
If you meant to say "I don't understand why so many people are surprised by this, considering that Granger has been on the team this long" then perhaps that's more like how you should have stated it. No part of your post showed that was the context that you were using it in. In fact, I read it as just the opposite. The entirety of your post was that Granger is a JW and that he doesn't acknowledge the National Anthem. If you were relying on context to make up for the fact that your statements lack clarity, then your post should have mentioned something about how this should be common knowledge.
If you believe that I'm taking it out of context, tell me which part of your post indicates that it's surprising that not everyone knows this.