Starbucks uses espresso machines that cost 4-5 figures. They have automatic thermal control. They never boil the water. While I agree with your overall sentiment, claiming that Starbucks makes coffee too hot and thus tastes bad is nonsense.
I'm from Portugal and we have a strong espresso culture, as in 90% of the people probably have multiple espresso every day. Many Portuguese agree that Starbucks espresso sucks compared to most conventional cafes. At most people go there for the American type drinks, which are a complete different style (and the coffee flavor hides behind all other ingredients, it doesn't have to be that good).
The previous comment didn't say that Starbucks doesn't suck (they probably agree that it does -- I've never met anyone who really likes coffee who doesn't agree that modern at-scale Starbucks is awful), they just asserted that the badness there is not explained by faulty temperature control.
I'm not speculating why Starbucks coffee tastes how it does, I have no idea there. It's just a handy medium for comparison because a cup in Laos is going to taste the same as a cup in NYC. And while they don't make great coffee, they also don't make horrible coffee - and so I think beating Starbucks is a pretty good and understandable baseline to aim for.
The more you roast the beans, the less terroir you taste, so you can use cheaper and less uniform beans. In Starbucks case this has become a brand identity, so it has persisted past strictly practical concerns. Many people dislike the kind of acidity and strange flavors you can get from lighter roasted coffee, at least in the milk drinks they want to sell, and light roasts are also harder to get perfect and consistent, so that is another point against it (or the same through a different lens)
Personally I prefer a light or medium roast over an Italian or French roast, but many people disagree
