Yes and no. The big items being discussed in the industry (electrical and generation/RMR world) is the effect of the environment and the dirt/surface contamination. The units just haven't been out there long enough for them to answer that yet. Warranty is one thing, but it's also very easy for the manufacturer to get a unit and then clean for their purposes and test accordingly. We had to go through this with a bunch of emergency phone towers powering a light and a cellular communicator. The units wouldn't and couldn't keep up no matter what we did and were within spec for general output and voltage yet when sent to the manufacturer, they took the glass and basically just buffed them out (want to say cesium oxide). Warranty replacement denied. Same thing goes with dust and surface contaminants....you can clean it off and be right back to square 1 in a day or two (or during pollen season).
The leasing companies are in the business of selling the lease. While they do stand to lose some revenue, until it's more cost effective for them to roll a truck and pay the tech to clean and test the units than eat the loss, it doesn't make sense for them to PSA them. I'm sure the contracts cover a basic maintenance scheme, yet everything else is billable, it's the only way to make sense on the design/build investment.