"Booshwah" is the phonetic form (the pronunciation) of the word "Bourgeois." Bourgeois basically means "middle class," and it is often pejorative. Middle class folks pass "human capital" (middle class values) down to their kids, and it helps their kids navigate the capitalist system in a way that emulates, at least, their parents socioeconomic success. The term can be pejorative, especially when it implies "Philistinism" (the middle class have enough money but no culture). They often are "white bread" types who work to afford a semi-expensive lifestyle while not taking enough interest in artistic and intellectual pursuits. Marxists' use this term in relation to the idea that capitalism degrades people by making them a part of the so-called rat race.
As a criticism, the Bourgeois (Booshwah) can mean "trashy middle class people." "Philistinism" is implied. People who make enough to have the house, lawn, white picket fence, boat, and 2.5 kids (the American dream), but they tell their kids to get a degree in something "practical." They aren't juggalos or anything, but these people seem like they should have less of an excuse to watch stupid shit like the Transformers films because they aught to be able to afford to purchase at least a little class.