Could somebody please critique this poem?

My first-grade teacher said, "To do your best

in all your classes it would you behoove,

so when from time to time we give a test

you'll always know how quickly you improve;

the subjects you most love you'll dazzle at -

if reading, math or science you have shown

to be your greatest gift - you'll then know that

to be the kind of work you'll do when grown.

For spelling words take out a clean new sheet,"

she told us with her canny eyes a-gleam.

"If all get A's by Friday, but none cheat,

the whole class will be treated to ice cream."

Back then, who'd guess success is competition,

most work mere techno-wage-slave exploitation

at endless hours of desk-bound inanition -

and all gifts fare for greed's mere despoliation?