Exactly. It's like if everytime you had a discussion of whether it's wrong to cheat on your spouse, it degenerated into a discussion of why it shouldn't be illegal to cheat on your spouse.
If you're deciding whether or not to cheat on your spouse, does whether or not it's legal even enter your mind?
If your friend came to you and asked, "What do you think? Should I cheat on my spouse?", you might answer "yes" or you might answer "no". But you wouldn't say, "Sure, because it's legal."