I'm a high school teacher, and I agree with you.  Not just because they worked well before, but also because I'm convinced those activities (cursive writing, memorization, etc.) build important neural connections that are important to learning.  Cursive writing forces the mind to concentrate and slow down, which helps wire the attention sections of the brain.  Memorizing builds important neural connections, consolidating learning into long-term, more easily-retrievable memory. 

Research also needs to be done as to the effects of diet and technology on learning.  I shudder when I see the amount of sugar and processed food many students eat; how a brain can function effectively on such a diet is beyond me.  The effects of technology (and the decreased attention span caused by it) also need to be studied.

The answer to the math problem is highly faceted....to just blame teachers (and I work with many really incredible ones) just delays real solutions to this increasingly dire situation.