I think it is tacky and I would find it rude as well. I know having a baby can be an adjustment for some but that doesn't mean everything else in your life stops. You still have to do all the same things as before. So I don't see why the MTB couldn't write out a few thank yous. Besides- isn't the shower held before the baby is even born? I don't mind if you use a label for the envelope but I shouldn't have to write it out for you. I took the time to get you something nice and come and celebrate. You can take 3 minutes to thank me without my having to make you do it. JMHO.
I so agree with this. I am sitting here reading these posts, and wondering who are all these women (barring those with high risk, medical issues) who can't address envelopes because they have so much to do before the baby is born? I worked right up until the time my first child was born, and when I was pregnant with my second, I had the first to care for. And somehow, the world turned, life went on, thank you notes got written, envelopes got addressed..