To Dave's original question which seems to highlight 'extremely':
I would say that rarely are the full costs considered by any facility in costing of the a round of golf in a cart, and so they are not extremely profitable
If we were to look at a real world, hypothetical test case, that both Dave is well aware of and one of the chief posters on this particular thread.
If we looked at St Andrews Beach, currently offering free carts (as a marketing incentive) with any mid week round. A course built on sandy coastal base, and without a permanent clubhouse so let's assume there is not a lot of budget available for capital expenditure. Sealed cart paths, from my recollections, are only of the steepest slopes - down to 1st tee, 16th to 17th fairway and 18 green back up to temporary house.
Now as will undoubtedly occur, pot holes, ruts etc will need to be repaired by maintenance staff, damage done to cart suspension requiring expensive repairs (say 20% of new ) especially after significant rainfall as we have had this year, eventually the prudent management team, super, members or guests say - please - seal all the cart paths, it will cause less damage to the carts, will reduce our repair and maintenance workload, will reduce dust in summer months, etc
I would guess this would be at least A$1 m, probably a hell of a lot more. (imagine trying to get fully laden cement trucks out onto a links course)
Add this to a cart fleet that needs to turned over every 3-6 yrs depending on the impression you wish to portray to players and visitors - 60 carts every 5 years - add another $75k per year. Plus cleaning, someone to get them out of shed each morning and put them away again at night, replace the odd dodgy battery, repair damaged seat, wheels, insurance, signage, etc
Cost to build a shelter shed and charging gear ? Realistically, probably at least $500k.
I understand that accountants can apply taxation, deprecation schedules etc - but at the end of the day, the club or owner still has to pay for it.
I know there is profit in renting our an item with a reasonably low cost with minimal actual maintenance comparative to income, but when infrastructure, that is usually buried under set up is taken into account, maybe it is not as much as the industry proponents say....and that the aesthetics do come into play, in perception of a golf course and it's quality and experience delivered to the players.