Why do people play 1 e4 e6 2 d4 d5 2 exd5?!
By the way, when I mentioned "Exchange Variations" of other openings, a couple of other examples come from the Old Benoni lines (1...c5 instead of 1...Nf6 and 2...c5). After 1.d4 c5 2.c3 cxd4 3.cxd4 d5, you have an Exchange Slav and after 1.d4 c5 2.e3 cxd4 3.exd4 d5, you have an Exchange Caro-Kann.
Same sort of thing when Black plays ...c5 on the second move not the first: 1.d4 Nf6 2.d4 c5 and now White plays 3.c3 or 3.e3, and Black captures on d4 followed by ...d5
Another sideline of the Slav Exchange can be reached via the 2.c3 Sicilian: 1.e4 c5 2.c3 Nc6 3.d4 cxd4 4.cxd4 d5 5.Nc3. Via a Slav move order it would be 1.d4 d5 2.c4 c6 3.cxd5 cxd5 4.Nc3 Nc6 5.e4
To cut a long story short: Who cares about the opening? Just get a playable position, and play on!
I wish I'd have gotten this advice when I was a pre-teen during the post-Fischer boom years, because practically all I did was study openings (but also at least some important endgames: knowing the Philidor position, and the Q vs c-pawn or f-pawn on the 7th, did save me some half points). Because of this bad habit, and only playing OTB chess on and off for the ensuing 40 years instead of continually, I only ever got to 1900+ USCF.
Now though I think the way you pick up openings is to go over master games. For instance I'm currently studying (actually memorizing) the games from the 1987 Kasparov-Karpov match in Seville, and am learning a heck of a lot about the Gruenfeld along the way. What's pretty amazing to me is that yesterday, I had a 1300-rated opponent reach the position after 14 moves of the 3rd game of that match in a blitz game -- didn't help me much, I played like crap (hung a piece, which he didn't accept, and then he resigned in a drawish position).
Likewise I think a good (better than training puzzles?) way to learn tactics is to play over complete games. Six books I just pulled off my shelf are "The Chess Combination from Philidor to Karpov", "Great Short Games of the Chess Masters", "Modern Chess Miniatures", "The Art of the Checkmate", "The Art of Sacrifice in Chess" and "Epic Battles of the Chessboard".
Or you can combine your study of openings and tactics. I have 2 of 4 of Nesis' (former World Correspondence Champion, in the pre-engine age) books from the 1990s, so the exact variations may be a little dated, but the fundamentals remain. Those books are:
- Tactics in the French
- Tactics in the Gruenfeld (I own)
- Tactics in the King's Indian
- Tactics in the Sicilian (I own)
Now I need to get back to training, Texas Amateur Championship is this weekend. I know I'm slightly off topic, but if these topics ever come up, I can just point users at this post.
Ultimately, it does us little good to ask such questions. The bottom line is that they just do. We may believe them naive or ignorant; we may believe their choices to be objectively unsound or psychologically dubious, but its up to us to prove it, which, at club level, will often be beyond many of us.
In the specific case of the French Exchange, I tend to find it quite difficult to meet. In particular, the usual recipe recommended by the books, i.e. a setup with knights on c6 and e7 with queenside castling is something I feel is actually quite risky for Black. White's attacking chances seem overall somewhat better than Black's in this line, with the hop into c5 by a white knight after c3 and b4 - hitting Black's queen on d7 - seems qite awkward. Meanwhile if White simply chooses to castle on the same side I find it very difficult to achieve any useful unbalancing of the position.