Why send money just because?
People are then going to ask why they are sending the money instead of lowering federal taxes and increasing state taxes.
The truthful answer “we’re taking money from your state and giving it to another state to subsidize them” is going to tick off the rich states and lead to resentment.
Further, they will still be left asking “why do they need my money?” and “what are they spending my money on?”
Saying “we’re making sure all kids get a decent education” Is much more palatable than “whatever they feel like” even though the money no longer allocated to education is then spent on whatever they feel like.