When you bring wine, you should expect it not to be opened. It is a gift for the host(ess) for them to do with as they please. If you don't like it, bring another hostess gift. Anyone who serves "cheap swill" at a dinner party is likely clueless when it comes to wine, otherwise they wouldn't intentionally embarrass themselves by serving it. In the case of someone who knows how to pair wine with food, bringing a bottle and expecting it to be opened is presumptuous as the host(ess) planned the menu and selected what they felt to be the appropriate wine. The only time I would expect a wine gift to be opened is if I contacted the host first, asked if I could bring the wine for dinner and asked what was on the menu.
The letter writer should probably stick to flowers.