I'm not disagreeing that it's okay to drink in moderation while nursing, but wanted to share my experience, and why I quit drinking (for the most part) during nursing.
I planned to nurse until my daughter self-weaned (which she did at a quite advanced age). I'd drink in moderation, but one evening as I was cracking open a beer after confirming we'd go out on the porch and nurse in our rocking chair, my 1 year old, who was just learning to speak, said Nooooooooo! with an anguished voice. I said What??? She said "Yuckyyyyy!" After a few exchanges, it became clear that not only could she taste the alcohol in my breastmilk, but that she found it distasteful. I set that beer aside in deference to her. I always wanted nursing to be a comforting experience for her, of course! and it clearly was not after even one beer! I consider it one small and temporary sacrifice of parenting. Again, am certainly not telling others what to do.
My mom insisted that I hated the taste of her breastmilk when she ate broccoli, so she stopped eating it while she was nursing me. This seems like the same sort of thing. They do say that your breastmilk can change taste depending on the food you eat, so that makes sense.
My son hasn't objected to the scotchy taste of my breastmilk, so I guess it's all about what you like!