Only because the market has developed around boat owners who all have trucks and trailers. In places where this isn't the case, dry and wet docks are plentiful and affordable. How much better would it be to have a service come pickup the boat and drop it in the lake for you and by the time you get there Saturday morning it is fueled and ready to go.
The post WWII rugged, independently capable of all feats American has been a horrible target for the populous. Weird given that WWII was the epitome of teamwork and interdependence in all things. Really the only distinguishing feature from today's specialization to the point of incompetence 2 degrees to the left or right, is entirely the idea of having perspective enough to go grab the right person for a given job or realize one must imitate it for a bit.