It's more likely to be down to incompetence. I can't imagine the party UV lights are more expensive than the fuck-you-up UV lights.
EDIT: Someone else mentioned these might've been used during COVID for sanitation, and are extremely cheap leftover wares now that the pandemic is "over", which would actually make them a lot cheaper.
Never attribute to malice what can be explained by plain incompetence is a saying. But I think a new modern corollary can be made. Never attribute to incompetence what can be easily explained by greed, which just circles back to malice and is stupidity at the same time.