As with all travel hacks that clearly break the rules but are often tolerated, it's better IMO for people to know the possible consequences. Those consequences might not even occur today, but in a few years time when the account is audited for some entirely different reason - perhaps mistakenly - but the OP can no longer credibly claim to have acted impeccably according to the rules. YMMV...

I certainly do agree that historically most US hotels simply didn't care. But with hotels cost-cutting right and left, who knows how many hotels have elite benefits / points fraud on their radar...