Since the emergence of small breweries, beer has become more like wine. There is a seemingly infinite number of brands and types of beer. Everyone has their preferred beverage. However, one can not reasonably expect international mass market cruise lines (or their local watering hole) to stock hundreds of craft beers and/or wine vintages to provide everyone's favorite.
My preferred brew at home is Yuengling Lager (aka the nectar of the gods). It is very good, reasonably priced, and most everyone likes it. It is mass produced. I have never seen it on a cruise ship. I view it as an opportunity.
I use cruises as an opportunity to try out different brews. Unlike a case, it is only a one beer commitment. If I like it, it becomes my beer of the day. The next day, I start the process all over again. It can be a challenge on a 14 day cruise to find 14 non light beers beers that are not served in aluminum bottles.