I'll Bite.
From a marketing standpoint....
When an RV comes from the factory, most come with a fairly standard Circuit breaker box that is installed the same as a residential unit. This almost never goes bad and parts are easily available at a hardware store. It gets it's power when we plug in at the campground. It distributes power just like in a standard house so again parts are readily available.
Connected to it is also a converter that as said changes the 120VAC house current into 12VDC to charge the batteries and power the 12V system which is all of the basic stuff needed to run an RV as they are designed to not need the 120VAC system just to operate the things like the lights, water pump, some vent fans, maybe some appliances. Most of this 12V system is standard automotive stuff so again parts are easily obtainable and so far all of these systems are easily repaired by most handymen.
Now where you might be looking for things to add or to help out in this market....
Inverters. Some RV's come with Inverters and most do not, but they can be added. These allow a person to run small electrical devices off of the battery for short periods of time. These can be a little tricky to install but with research and Youtube and asking questions to the experts on this site, most of us can do it.
Solar Systems. Don't come standard on RV's but many add them so that their 12V systems can run longer without needing to be plugged in. Installation is same as above, easy with some help from this site and the internet.
Generators. These come standard on most motorhomes and a few trailers, but RV'rs like to have them, and some are added to an RV or portable units are brought along.
Anytime you can make any of the above Lighter, More Efficient, Cheaper, Longer Lasting, more powerful, or Lighter (yes I said it twice), then you get our attention. This includes things like the appliances, A/C units, right down to the light bulbs.
Now Maintenance.
Houses get maintenance from an Electrician, A/C repairman, Plumber, Carpenter, and Cars get maintenance from a Mechanic (even these get broken down to the A/C man, the alignment guy, the transmission or engine guy too). RV repairmen usually have to be all of them combined. Dealerships employ some of each. Depending on the problem will depend on who gets chosen to work on it. Most of us on this site seem to use this site for the wealth of information that we have when we combine all of our strengths and we tackle most of the repair work ourselves as long as we don't need huge tools or facilities, and are physically able to do it. You will find in RVing that many of us are up there in age and will sometimes rather pay someone to do it rather than test our capabilities. Some RV repairmen are mobile as in they come to you with a van full of tools and supplies. These are great too especially for fulltime RVers who can't easily leave their RV at a shop. If the engine and/or drive train need work it will most likely go to a automotive or truck repair shop.
My RV is only a few years old so mechanically I haven't had to call anyone to fix anything yet and I have been able to fix or replace the small things that have happened myself, and even the upgrades I would like to do I have all of the help I need right on this site.
Hope some of this helps.
