So, I'm a long, long way from needing to worry about RMDs, but want to understand them better. And I have to say that I simply don't get what the goal of RMDs is. Wikipedia says that it's to limit situations where a retiree passes a large tax-deferred sum to a beneficiary. But as I understand it, the beneficiaries can either take distributions over several years (and pay taxes on them), or in the case of a surviving spouse, they can roll it into their own IRA, and defer taxes until 59.5, or whatever.
Or, put another way (and yes, I'm simplifying here), in the current situation, the retiree could take the RMD, pay the taxes, and invest the rest in a taxable account. Without the RMD, the retiree's IRA would pass on to their kids, who would then take distributions and pay the taxes.
In either case, the money (and the gains) get taxed. So what's the point of forcing the money to be withdrawn and taxed during the retiree's lifespan? What am I missing here?