Perfectionist

If you remark that a proposal or claim should be rejected solely because it doesn't solve the problem perfectly, in cases where perfection isn't really required, then you've committed the perfectionist fallacy.

Example:

You said hiring a house cleaner would solve our cleaning problems because we both have full-time jobs. Now, look what happened. Every week she unplugs the toaster oven and leaves it that way. I should never have listened to you about hiring a house cleaner.