Of course women don’t like being reduced to names. But all hetero males do it. It starts with little boys in grammar school and no matter how old you are it never stops. Now this is not something that a normal guy would ever say out loud to a woman but they are thinking it just the same. Human nature has embedded this into the hetero male DNA. It’s not a denegration of women. Every male has a mother, sister, or daughter and would never want them disrespected.

As far as male slang terms for vagina, I think it’s a long list. Though I don’t think women use many slang terms for male anatomy. I’d guess because sex for a woman is mostly emotional. For a guy, while it may be emotional it is foremost a fun physical activity which makes it easier to joke about. Remembering back to my grammar school days, I believe the origin of “beaver” is that back then women had lots of pubic hair. Pubic hair trimming and “landing pads” were not in vogue. And the pubic hair surrounding a vagina sort of had the look of a “beaver”.