It's very simple, really. Business that want cheap IT workers give PAC (Political Action Committee for non-US readers) money to the relevant House representatives and senators to make sure their needs are known. The laws with quotas are adjusted to meet these need.
When is the last time you gave money to support your candidate to the US Congress and asked them what you want? And, taxes don't count!
Have you ever written your congressmen about H1B workers?
Calls to patriotism (or nationalism) is a tool they use to manipulate you, not the other way around. Please, know your place in the scheme of things.