What people now refer to as cruisers, were once just regular bikes. Things that people traveled and relied on. Back when bicycling was an activity, not a sport. I think the term "cruiser" or "beach cruiser" came into parlance at the tail end of the 1970's or so. By then, most bicycles were "lightweights" (drop bar 10 speeds, 3 speed tourist, etc with 1 3/8 tires or narrower). So the cruiser became a nostalgic throwback. And they never really went away.
I personally think most of the aversion to cruisers is simply some don't want to be seen on them. The more I ride my drop bar bike, the more I appreciate getting on a 40+ lb upright bike with a wide seat and cushy tires. Yeah, I get worn out faster trying to maintain a 15mph average pace on a three speed bike of that heft. But I've done 50 mile days on them with no problem. There's something to be said for slowing down and enjoying the ride, and like with motorcycles, it's definitely more fun to ride a slow bike fast, then a fast bike slow.
If you're still in the decision making process, don't get all hung up on weight and features. If you're going geared, three speeds are plenty. I pull a 100lb trailer with a three speed 45lb middleweight from the 1950's. It's no biggie. Obviously hills factor into the equation somewhat, but I still think 3 is enough. I'd buy used, and if it doesn't work out, you're going to lose less.