Wish I could find a better mouse I like as much as this one that I didn't need to pay a yearly subscription for. It's just the right size, lightweight, wireless, and being able to store the customizations to on board memory is nice.
Not trying to invalidate your experience -- I've see with my own eyes a similar thing happen with rubberized coatings on laptops & keyboard wrist rests (other's not my own).
Just putting it out there that it's by no means the universal experience.
Everyone had the horrid goop issue as well, you're not mad.
https://www.reddit.com/r/logitech/comments/1nq2luo/got_the_m...