That's a straw-man fallacy. Just because you're trying doesn't mean you have to be perfect right away.

I also believe that we have all reason to go completely vegan long-term. Thanks to food-science, it's not a radical shift anymore, just a slow adjustment and a little bit of discipline until you've adapted that new habit. I was a very much into meat and slowly adapted to a vegan diet, it get's easier over time until a point (for me at least) that you even prefer the vegan/vegetarian option.