Dude, ALMOST everyone smoked and drank coffee back then. It was the rule, not the exception.
And how do you quantify "quite a few people"?
US history is US history. That doesn't mean your teacher is the all-knowing source of information on baseball factoids. Most historians have areas of expertise. Simply being certified to teach AP US History doesn't make him an expert in every field of the subject.
I mean no disrespect at all, but you really need to start questioning things you hear instead of blinding accepting them.
Do you know, for example, what the percentage of Americans who smoked back then was? Do you know, for example, what IF ANYTHING, the correlation is between tobacco use and increased proficiency in sports? I smoked for 35 years. The one thing I noticed the most was that tobacco had a NEGATIVE effect on my breathing, running, etc. It did not improve any of my skills in any way, shape or form.
If you're in AP classes, don't accept things as fact just because a teacher says them, especially if they're subjective comments like this. Ask questions. Determine for yourself whether or not the statement is fact or opinion. And to go one step further, make sure the fact is appropriate and valid for the discussion.
Tobacco doesn't improve athletic ability. So the fact that Ruth used tobacco is irrelevant in discuss how that could have influenced the number of home runs he hit. If anything, the fact he was a habitual smoker - primarily of cigars - might indicate he would have had MORE home runs not less.