That's an extremely oversimplified and biased explanation of the match's creation. It is true that the match was created to curb poor behaviors on the part of programs, if that's what you're getting at. With no match or rules, programs were free to fill their spots at any time, with anyone. This led to earlier and earlier application deadlines, exploding offers, and other shenanigans -- partially driven by the imbalance in applicants and spots. The match fixed all that, brought order to the chaos. It allows applicants to interview at multiple programs and not worry that they are going to "miss out" on a spot because of an early offer. It's the best logical solution to the problem of assigning spots to applicants that gives most people the greatest option and degrees of freedom.
No system is perfect, and the match is no exception. People who have a clear interest in a single program can't just interview at a program, get a spot, and be done -- they must interview at a bunch of places and rank them. Earlier offers to people might yield more efficiency -- but perhaps at the cost of applicants feeling like they have "lost out" on their reach applications (i.e. getting an early offer from a program that will be low on your list - ? take it or let it go and hope something better comes along.
In many ways the main problem with the match is that it takes all the emotion that's usually invested in an application cycle, and concentrates it into a very small period of time.
Back to the OP's comments, we can't just "do it like undergrad". Undergrad institutions offer more spots than they know people will accept, knowing that a bunch will decline. if they end up with more people than they can really fit, they just find a way to make it work, or encourage some people to defer. In residency, there's an exact number of spots we have -- we are not allowed to have one more (and since these are paid positions, we don't have the salary to pay extra people). So, if we were to use the same system, some small number of people would get multiple offers, and a large group would get no offers. As those initial people chose a spot, then more offers would trickle out. It would be horrible.
Although ranking may seem weird, it's simply asking you: if you got an offer from all of your programs, which would you take? There's no "financial aid" consideration like undergrad, you already know the salary and benefits of every spot. Whatever program that is, it goes in your #1 spot. Then, what if you got an offer from everyone but that program? That goes in your #2. And so on. The best strategy is to rank programs in the order that you want them -- no amount of trying to game the system will work any better. And the same is (basically) true for programs -- they should rank candidates in the order they want them.
There are threads here about possible improvements or changes to the system. Discarding it completely would be an enormous mistake for students, IMHO.
