I didn't change my last name when I got married, but it wasn't out of a desire to keep it, or to make a statement, or anything. Honestly didn't even put much thought to it at all. Didn't see a reason to do the paperwork & get new ID's and credit cards and such. I just didn't (and still don't) give a rat's ass and neither does my husband. *shrug*
If he would have, for some reason, had an opinion on it and wanted me to have his last name, I would have changed it simply because it was important to him. But since he didn't, apathy won