I think some opening theory is mandatory for a chess player trying to get stronger. Of course you can learn by experience only, but that really is the same as opening theory without labels to order things and structure your thinking.
I agree that playing opening moves learned from a book mindlessly is no fun, but understanding the dynamics and strategies of a opening is really the point of opening theory, and that is fun to me. I have a encyclopaedia of chess openings, but it doesn't really spell out why some things are considered good or bad. As a consequence it is extremely dull and hard to actually use in a good way for a player at low level chess.
The best chess book I have is "Mastering the French" by Neil McDonald and Andrew Harley. (you can read some reviews on Amazon
here ) It breaks down all the French opening lines by looking at the resulting pawn structure and organize the chapters according to this. It also graphicly shows all the important "power squares" and potential ways for the pieces to move, both for black and white. Then you have a few illustrating games with every chapter to play through. Works amazingly well, and as you say Letum, no need to learn a lot of names and lines, as the book shows you the most important things to consider for both players, depending on the pawn structure.
cheers Porphy