Peter,
Is this true when you are playing your home course, which I assume you know intimately, including all the architectural features. It's easy to play a very familiar course by rote after hundreds or thousands of plays. Do you find the same if you are playing a less familiar course.
Patrick,
I've had a Bushnell for a few years now. On my home course I used it sporadically at the begining to verify yardages on other markers. Since I know where all the sprinkler heads are and I don't like taking the range finder out and putting it away, I generally use the sprinkler heads. I used it after that to verify carry distances for creeks and ponds and traps. Once I had confidence on those distances and what I could do on each, depending on conditions, I stopped using it there. I use it at new-to-me courses, more for assessing hazards than actual distance to the flag. Consequently, I'm not tunneling, because I'm using it in assessing features.
For those that use it for distance to the flag, I think it is of minimal use for others than elite golfers. I'm reminded of a time some years ago when I played a corporate scramble with a couple of friends who were 6 or 7 handicaps at the time. The corporation had hired Roger Maltby to speak at the dinner and to stand on the 7th tee - a par 3 - to meet and greet and to hit a ball for each team on that hole. Smart guys we were, we asked him about the yardage and wind, etc. He told us and then says, but why the f... do you want to know all that stuff - you have no clue how far or what direction you're going to hit it. Properly put in our places, my two friends put their balls in a pond and Roger was well inside me on the green. The lesson - even single digit 'cappers have little clue within 15 or 20 yards about where they're going to hit any particular iron shot to a green. So, the accuracy for us is a bit of a waste. For an elite player or pro with more consistent contrl of their shots, I think it would be very valuable. I'd bet elite players, especially in competition are less likely to tunnel. I've never found that the range finder lulled me to sleep on the features on courses. Boredom with a familiar course is a way more likely way to induce tunneling imho.