I think we need to explode a few myths here.
Low use of diesels is a good thing.
This is categorically not true. Diesels are designed to be used and used frequently. Studies have shown that a diesel
that is frequently used will have 3-4 times the life of those that are not.
Further diesels are generally the best source for charging
house batteries and generating hot water
in the shortest possible time.
Sailing is free
Again categorically untrue. Abrasion of sails
against stays and stretching. Chafe on the halyard
. Wear on goosenecks, furling equipment
and blocks. This all costs money
in the longer term.
Most cruisers enjoy sailing passages
Based on the comments on this forum I am sure that there are those that enjoy the sheer thrill of sailing for sailings sake. Give me a half day out on a fast boat in good conditions then I am there. However, I have yet to meet anyone, and I have talked to hundreds, who tell me that they particularly enjoy passages, especially extended passages with overnighters, from place to place. Rather the discussion seems to revolve around the most efficient means to get the boat from A to B so that they can enjoy their next destination
Depending on sea conditions my boat is capable of moving from point A to point B with one motor
at 7 knots, so if I can sail faster than that I will. Otherwise I will motor/sail or motor. If I cannot make the rhumb line under sail then I will use the advantage of motors in conjunction with sail. Not withstanding those that will now say that they do not do this because of some philosophical whimsy, I believe the vast majority of cruisers will use the motors if it is sensible to do so.
Now some monos and cats sail better at low wind
speeds so they will spend more time sailing, but in return for this generally your general living comfort is reduced. Others want more comfort and as a general rule
their boats take higher winds until sailing is optimal. These are personal decisions.
As for charterers it seems to me that generally in order to defer cost they pack as many people on board and wish to get to as many places as possible in the shortest possible team with the least fuss. It is no surprise to me that they motor most of the time.