While similar questions have been asked before and many comments were given, I couldn't find a thread dealing with my particular experiences. So:
Whenever I discuss openings with professional and even with semi-professional players the issue inevitably reaches the point where somebody says that he doesn't like a particular line because he would have no prospects of winning this position at all - meaning that it is equal and dull, too drawish etc.
This fear is not foreign to me but after all those years I concluded that it is hypothetical in nature. I played several thousand classical games but I cannot remember a single one that resulted in a draw exclusively due to both sides knowing a long main line. Very seldom did I reach a position after about twenty moves that a book's author evaluates to "=". And even in these rare cases, the rest of the game saw complications that granted winning chances to one side. Without checking it, I guess I had more decided games then draws in the Exchange French and the Exchange King's Indian.
Even on low GM-level I don't have the feeling that this is a common scenario. In the few cases I witnessed a GM game where both players were blitzing out their prep and agreed to a draw quickly, I never had the feeling that one of them was disappointed and doubted his opening choice, although this is different on world class level.
For some years now, I bring up this point again and again - this "empirical" objection to a concern understandable form an "analytical" perspective. But it never catches on. (Most surprisingly, a lot of people expressing this concern also show a tendency to make quick draws.) Recently I heard of a talented 9-year-old. His caregiver was concerned that he exclusively plays the Petroff against 1. e4. His supposedly weaker opponents learnt about this and prepared drawish lines against him. As it turned out, during that tournament he didn't draw a single game in the Petroff.
So to my eyes, this is an unjustified concern for players below, say 2500. Sure, you can loose half a point due to being out-prepared. But not in lines of which you know the details. But nonetheless every opening adviser seems to be proud to state that a certain position is full of life, although there is no objective advantage. I wonder whether I am misled by my subjective experiences. Is the scenario of a fully bloodless game more common than I am willing to grant? Is there anyone who is experiencing this regularly? And anyone who got so bored by this that he quit chess? And if not: Why is this concern so pervasive anyway? Might it be that weaker players mimic super-GMs, pretending we all share the same problems?
And if someone shares my feelings: What is the threshold above which this becomes a problem?