[ghaff]

It’s mostly (with some exemptions) formal policy from the IRS. I suspect the real justification is that a lot of these things are hard to value, the numbers are small in the scheme of things, and compliance would be very low. It actually makes a lot of sense not to put a rule in the books everyone would ignore.

[dragonwriter]

That makes sense, more of an administrative optimization around thw current conditions than an administrative failure.

OTOH, that makes it an unstable thing to build a business model on expanding, since the more significant it becomes with entities other than credit card firms exploiting it as a marketing and loyalty tool, the less it remains the case that it is efficient to let it slide.