It took nearly a year before these reports started actually becoming a real thing, and even then it was unclear how widespread the problem actually was. MS didn't know what the problem was for a good few months.
Hindsight is 50/50 but they would have required a whole year of extra testing to test for something they would not have even been anticipating in the first place.
They thought they had a readily functioning console from the tests they had done and thought it was ok to launch. Its not about rushing, or incompetence, just bad luck.
Sorry, bad luck doesn't explain 50% fail rate.
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"
Azzanation: "PS5 wouldn't sold out at launch without scalpers."