If my fellow citizens agree, why not? Are those who oppose most abortions but support, say, parental notification laws to be condemned for "incrementalism"?
Why not? You propose a law you can pass now knowing full well you're going to amend it later to more of your liking?
Why not? Because it's dishonest and deceitful, that's why not. Oops. Those are moral concepts -- you don't understand those, do you?