"Always solving capture moves will not help to solve mates in 2 (considered as weaker)."
I think this is a good point, I just question how many people there are that can solve the complicated exchange puzzles in the higher ratings that would gain much from solving the straightforward mating sequences of the lower-rated puzzles. There's a reason the lower-rated puzzles are rated lower, and it is because a greater number of people playing them find them solvable. That's the point of the rating system, and any other chess rating system: The higher-rated ones are harder to beat.
There can be complicated and hard-to-find mating sequences, too. They just, by definition, have higher ratings. Searching for easy (easy is relative and subjective, of course) mate-in-two puzzles is still only helping to solve easy mate-in-two situations.
I think this is a good point, I just question how many people there are that can solve the complicated exchange puzzles in the higher ratings that would gain much from solving the straightforward mating sequences of the lower-rated puzzles. There's a reason the lower-rated puzzles are rated lower, and it is because a greater number of people playing them find them solvable. That's the point of the rating system, and any other chess rating system: The higher-rated ones are harder to beat.
There can be complicated and hard-to-find mating sequences, too. They just, by definition, have higher ratings. Searching for easy (easy is relative and subjective, of course) mate-in-two puzzles is still only helping to solve easy mate-in-two situations.