Elizabeth, most regular sized curvy women - in my experience of dressing women for a living - are against masculine shirts because they think they have to be fitted which causes a challenge on the bust and torso. Actually these days they shouldn't be fitted to look fashionable, which I am shouting from the roof tops. Most don't want to send stuff to the cleaners, nor do they want to iron themselves. Furthermore, women feel too formal, stiff and business-y in a shirt. Or too masculine. Also, the collar is not the best match for those with a short neck.
Interestingly, my plus sized curvy clients love to wear fitted shirts. They enjoy the structure, polish and forgiving fit on the torso.
It's true that straighter bodies are easy to fit into button downs and LOVE wearing them - Suz, Viva, IK, Inge, Merwoman, Tex, Gracie, Claire and I raise our hands. It's like the planets align when we wear them - it's a magical fit almost every time.
Mary, a fashionable oversized look should eliminate most of those challenges. As will one in a softer fabric.
