This is buildings. It could be just the usual resistance to change. Some companies have been installing gas or oil for decades, they know exactly what they are doing, how to calculate those systems with just enough margin. And the cost for “not working” is very high. So here comes some new tech, and they will suggest to build it too powerful just in case, and do extra stuff that doesn’t make sense except to keep the option open to install oil or gas later in case it doesn’t work. And the result is too expensive, so nobody wants to pay for it, and so they never gain the confidence to make it cheaper.