If I have to purchase a special tool to open a bottle, I would rather purchase a product that isn't hard to open. That is my standard for all sorts of packages from food to cosmetics. Even a grip can be hard to manipulate. So despite having a fondness for Diamine, there are plenty of other inks on the market with caps and bottles that are manageable. At least in the U.S., the population is aging. Companies don't have to take that into consideration, but those that do, will reap the rewards.
From an aesthetic standpoint, I found the form of the old cap to be attractive. The new one, not so much. Maybe the old cap would not fit the new bottle. But gold? Black would have been my preference. Neutral and simple especially in contrast to the complex label. The label and cap compete so your eye does not know where to land. It's a basic design principle that wasn't applied to the new packaging.
I see what you are saying about rather getting a product that is easy to open to begin with. And I agree that the cap isn't as good as the old one. However, I'm mostly in the school of thought that purchases bottles of ink for the ink, rather than the bottle. I have of course purchased empty bottles before to decant inks into. Inks bottles like Noodlers for example leave something to be desired in the aesthetic area so they get decanted into MB bottles.
But as you said, getting an empty bottle sometimes requires an additional purchase unless you already have one lying around, and doesn't help at all if you can't open the bottle-to-be-decanted initially.