I can see both sides of this, at once, like I'm looking at an ambiguous image: duck, or rabbit?
On one hand, it's absurd: "Electrochemical system is changed by electricity! Shocker! Be afeared'n'affrighted!" The brain is a physical system, your personality is a result of the behavior of that system, so changing the physical system is going to change the personality. It's a more controlled version of Phineas Gage and the railroad spike.
(Plus, dirty little secret: Electroconvulsive therapy works. It has nasty side-effects, but it makes depression go away rather quickly. So the basic idea of chasing away mental problems by shocking brain tissue is not new, despite a decades-long effort on the part of artists to make people think ECT is simply meaningless torture.)
On the other hand, I can see how this would be challenging to someone who finds emotional states deeply meaningful, especially if they (as most people who look for "meaningful emotional states" seem to) find sad states more meaningful than happy ones.
It's the myth of the happy pill, by which I mean the myth that depression is this wonderful, meaningful Long, Dark Night Of The Soul and that taking something to fight it is "making you feel better" in a coercive sense, and depriving you of that meaning, and, possibly, preventing you from getting to the root of the problem, which must needs be done through talk therapy.
My conclusion is this: Emotions in and of themselves aren't meaningful, treating symptoms doesn't mean you can't also look for root causes, and, sometimes, an organic dysfunction is the root cause, as opposed to something you can talk out.
Why? Because the implication of a 'happy button' in the hands of everyone and anyone horrifies me. Sure, you and I might have better things to do than to hold that sucker down and experience unending monotone bliss for the remainder of days, but how sure are you that the majority of humanity won't? How many lives might be wasted because someone's instinct was to go for immediate bliss instead of trying to make things better in the long run? It'd be the final drug.
On the one hand, it's sort of scary. On the other hand, what are you supposed to do when nothing, not art nor work nor drugs nor thought, does anything to ameliorate the pain?