Focusing on whether or not the Cruise industry is being singled out based solely on a mask requirement is woefully lacking in scope, as others have said here, other transportation industries are obviously essential, and necessary to keep the population from starving, or dying from lack of ability for important front line workers from being able to travel. And as far as I know MOST (I haven't verified) U.S. domestic airlines are requiring passengers and crew to wear face coverings while on board planes so that point is again moot. The singular issue with cruising is that it is a "recreational" activity, thus NON essential, as is currently the norm, travel between international borders (flights and road travel) that is considering non essential (not for commercial cargo or food) is prohibited in and out of the U.S. right now. So until they re-open international travel and the ports that most cruises visit on their itineraries re-open (not just one or two but ALL) resuming cruising is really not important enough to risk the crews and passengers for any cruise line to take. I know there are some European cruise lines that will resume cruising at the end of this month or shortly after, but they've mitigated their spread of the virus on ways that the U.S. hasn't been able to do, which includes requiring citizens to wear masks, effect hygienic practices and remain in lockdown in ways that many here in the U.S. have simply refused to do. When you have a state recording 15,000+ new infections in a single day, resumption of a leisure industry in that state simply doesn't make any kind of realistic sense. If the CDC extends the order it is likely because they feel it has to in order to try to keep infections from being spread on board among passengers that could potentially spread it at foreign ports, amongst themselves and then potentially world wide again.