It's arguable that it was by design as APC was also in the business of selling very over priced battery packs.
The good old days of IT being as many free UPS as I could carry, only that they all needed new batteries and some needed full disassembly to remove them!
I personally never saw one on fire but did attend a site where the cooms room was VERY warm and VERY smelly with a somewhat rotund APC bleeping away.
We had the not so fun job of taking apart entire football length racks. More than 70% could not be disassembled and thus a custom portable overhead (I beam) rail system had to be deployed to pick up and shuttle individual racks to the exits.
A fully loaded symmetra UPS is thousands of pounds.
It took no less than five men to shuttle the individual racks on to dolly’s for the last dozen meters.
Start to finish it took 14 months to get that data centre back up after the insurance claim was approved. As an aside this incident had to be the histories worst timing scenario as the old halon fire suppression system was just being removed to use the more eco friendly system.
Just one week later and the damage could have been limited to just a row vs the entire building.