You have to like pages from your personal account for it to count toward number of fans, so I actually prefer it when people post their link on my wall (using their personal account). Otherwise I have no idea who anyone is!
I like to return the favor but I can't if I don't know their shop and there's not really an easy way to find it (you can search for their name on Etsy and if they have a shop, see if they include a FB link, but that's time-consuming). If I see personal likes without wall posts, I assume they either don't have a business page or don't care if I like them back.
I can see how telling someone they HAVE to like you back is annoying. I usually post with my business page saying hi, where I found them, and what my name is, so they can connect me to my personal account. It's less spammy than posting a link, but I don't mind if people do that for me. I mainly do it my way just because I prefer to follow and interact with fan pages from my fan page only (I hide fan pages in my personal feed so it doesn't get too cluttered).
As for it looking unprofessional to have all those links on your wall, it doesn't bother me. I figure it's free advertising for those people to anyone else who visits my page.