They are small population states compared to the very few that a candidate would need if they were going only for a national popular vote.
And of course, there are MANY states that are far, far less populous that would be totally ignored - despite their obvious benefit to the country for being a state.
Alaska, screw you with your teensy population!!
And NO, the FedGOV cannot just tell the states they will receive no money. Where in hell did you get that??? When the FedGov denies a state any money that they are otherwise given by Congress they have to have a specific and connected reason - like the 55 mile speed limit to get federal funds to fix federal highways.
In fact, the FedGov already tried to connect federal money given to local law enforcement with the sanctuary cities and the courts said “NO WAY” - even though it is clearly a law enforcement issue.