Because the Constitution also says that any bill requiring the action of both the House and Senate MUST go to the President for signature.
That doesn’t mean it shouldn’t be in every bill, and that the Congress shouldn’t fight the issue, but the president’s veto power is a consideration.
And if the President vetoes, the Congress can override the veto.
Congress can vote to suspend the Supreme Court rulings on gay marriage and even Obamacare.
And it can also say that the Supreme Court may not have jurisdiction over these matters in the future.
The Congress of today consists of people who are by and large bought and paid for toadies, ignorant of the Constitution and of their responsibilities.
If we had this bunch in 1776, America would never have been born.
Makes one realize what a God-made miracle the Founders were.