IMHO there's a BUNCH of good comments in this thread. Most of the time I only get to fish on weekends, and the lake is crowded. I get a kick out of watching people fish. Sometimes I learn stuff...sometimes I laugh. I think at least in some cases the Bass know when the people fishing leave. This Spring I was fishing a row of lay downs. A couple tournament "anglers" came flying up in their 70mph boat to the lay down right above where I was fishing. (~50 yards away) Both of them made 2 or 3 casts each, burning buzz baits around the lay down, then they sped off. I eased up right after they left and caught a fat 6 pound Bass on my first cast on a spinnerbait, into the lay down. It's my belief that they "woke" the Bass up, and it was aware when they left. I ease up there, made a precise cast, and the Bass thought it was breakfast time. I really hate they didn't see me catch it, since they cut right in front of me. They're casts simply weren't accurate enough to catch a big Bass. I made a super accurate cast into the cover, but I'll always wonder if the Bass hearing them leave helped me slip in and catch it.
In pressured water I believe the strike zone is tiny. I also believe the strike zone is usually bigger in non pressured water. I believe stealth is important in both pressured and non pressured water. Perhaps it's more important in un fished water, where humans usually aren't around.
I catch Bass behind other "anglers" all the time. What I see them doing helps me determine if I go in right behind them or come back later.
I believe lure selection is way more important in pressured waters. I also believe the latest greatest newest lure isn't always the ticket. I like going back to lures and techniques that worked decades ago that everyone has move on from.