If you are allergic to lanolin, then you will want to choose an acrylic yarn instead of a wool yarn, or even a cotton or polyester yarn. Allergies are the main reason I don’t like to use wool ...
Honestly, the only reason I can think of to not use Lanolips is an allergy to wool and wool derivatives. Since it's a natural product, some of you might be allergic. That's how it goes ...