The answer as to why is that the HVAC industry does NOT want DIY installations. Such stuff will hurt their bottom line don't you know!!! That is also why the companies usually will not honor a warranty unless you get a licensed HVAC to install the unit (they exist to srve the HVAC industry including the local installers... Also explains why these mini-splits are just not prevalent here in the USA (but that may be changing)!
Actually its already started changing as allot of DIY folks like myself who are made up of landlords, licensed handymen, and regular franchise food chain employees that wear Mc "D" uniforms to class are being seen in more local community college offered HVAC commercial/residential condensed 1 semester courses. Breaking away from the super high run-away cost of contracted maintenance and installation cost, something has to give. Like Yeldogt pointed out high pressure flex-hose with quick connect technology has with with us since since the 1970's. In the Navy as a young GM2 I used to assemble high pressure 2200 PSI flex house for weapon systems that were constantly moving hydro and pneumatics under terrible conditions and stresses, and never once did I witness a catastrophic failure. In fact most hoses were replaced in still working order after 5 years of use just for planned maintenance sake.
The DIY demand is growing and will soon change the way cooling and heating is installed and maintained. Not that long ago no one would have believed that elevator operators, phone switchboard operators, gas station attendant, cashier keypunch operators, telegraph, and even TV and appliance repairmen were once valuable skill-sets requiring highly trained and well paid people that no one thought at the time would ever be replaced. But technology, better methods, and consumer demands have made all those trades disappear. And the same is going to happen in the HVAC residential and small business market, in 10 years you probubly wont see any more "exclusive" residential HVAC comercials.
