“If people know that they are coming to shul and are going to be there for at least two and a half hours, of course they are going to talk!! ”
Of course? If one had to sit through a dinner at the white house and 2 hours of boring speeches, would he talk to the guy sitting next to him? Why should hashems house be any different. Perhaps this person should move to a minyan that davens faster, so that he wont be bored in shul. Perhaps the person is bored because they have zero appreciation of what it means to be in shul in the presence of hashem. Perhaps this person sees tefilla as nothing short of a chore, chalila, and thats why he is bored. There are many, many people who attend such shuls and are not bored, and in fact enthusiatically sing along with the chazzan, or listen attentively to every word of chazaras hashatz and krias hatora because they appreciate what it means to be in shul.