I think you yourself said it. You like going for these pretty configurations - where all the pieces are "neatly" placed and give you familiar movement and open spaces.
But then you are entirely thinking about your space and very little about what the opponent can do.
I know this because I blunder just like you. I am usually caught up spring cleaning my own house and the other guy finds some nasty tactics.
People at our level make this mistake all the time.
It's not about organizing your pens and staplers on your office desk. Is it? I'd know cause I do it too.
When he says things like how it's ok to make a positional concession as long as you exchange queens, I don't think that's good advice, or at least could be very misleading. Giving away advantages is precisely what can allow the opponent back in the game. If you give your opponent any sort of compensation, (e.g., doubled isolated pawns to attack) even if they are a piece down, it can make the game harder to play. And if you keep making those mistakes they can add up, and you might suddenly end up with a tricky position to win. You don't have to be a freak about every positional feature, but no need to be lazy either -- even if you can get away with laziness, it's not a smart habit.
In any case there is a fine line between playing safe moves and playing cowardly. If you insist on avoiding calculating anything, you will find yourself making many concessions and being too scared to find winning sequences to put your opponent away. You shouldn't invite complications of course, but don't use this as an excuse for outright paranoia; that can really affect you psychologically. Just turning your brain off and deciding you're not going to look for forks anymore is not something you should expect to get away with regardless of the material situation.
I say this because I was once on the "too cowardly" side, expecting to win all my won games without calculating more than a move ahead. The idea of "avoiding unnecessary complications" is an excellent one, but it can be taken too far; I have.