Maybe he's used Homestake because it's the gold stock that's customarily used to show how well some gold shares did during the 29-32 depression.
If it's been used to show how well the shares do, why not use it in a comparison with bullion?
And ... he's in the bullion business and therefore writes on its positives. Seems reasonable enough to me - he's in the bullion game because he believes in it, and writes on it demonstrating why he believes in it. What's wrong with that?
All in all, he's just giving his opinion. It's up to each of us to decide whether to give it any credence or not. It always is.