Maybe it's "just a motorcycle", but it's a damned expensive motorcycle and it should come with at least a minimum amount of quality and customer service as standard equipment. And for some folks a motorcycle is more than just a toy, since they use them as much or more than they use a cage. Harley shouldn't get a free pass because it's "just a motorcycle". That's about like giving a boat builder a free pass on a leaking boat because it's "just a boat".
Btw, did your dealer make any attempt to get the part expedited, or did he just put it on his regular stock order and sit back until Harley saw fit to ship one? I think I know the answer to that one. Parts can be ordered in various ways, with regular stock orders being the lowest priority and affording the dealer the lowest costs. There are higher priority ways to place orders for things needed right away, like highly essential parts for a unit down repair, but those cost the dealer extra. That dealer should have placed the order as a unit down or whatever term Harley uses these days, and he should have been on the phone with Harley following up on a regular basis. If he didn't, he deserves at least part of the blame for the big delay. As Twolane mentioned, Harley is still building bikes with that same master cylinder pretty much every day, so obviously there is no national or world wide shortage of those parts.
In some states with good lemon laws a person who had a vehicle out of service waiting for an essential part for 30 days or more would be entitled to a buy back of the vehicle. You can bet that the auto folks find ways to get warranty parts out to the dealers quickly in those states. If they can do it, Harley can do it. Next time this happens to anyone, don't assume your dealer is doing the right thing, ask them specifically what kind of order they submitted and get details, then contact H-D customer disservice yourself and ask them to expedite the part. Give them the details you got from the dealer to make their job a little easier. Be nice, but insistent. Tell them whatever story it takes to make them want to help you, like "I just bought this bike to make a special trip with a group of friends and all the plans and deposits have already been made".
You won't get much help on nonessential parts like the painted CVO stuff, that will take more time than normal off the shelf parts. But I'd still follow up on a regular basis to make sure they don't let it fall through the cracks.
Jerry