The North Face Baltoro HV 400

First snow of the season, so I pulled my North Face boots out only to find that the rubber lower portion of the boot has cracked and separated from the leather upper. I guess it isn't rubber but some kind of hybrid plastic.

These boots were only worn maybe a half dozen times. They are about 7-8 years old. The boots are crap, they should last longer than this. They should not dry rot from non use. My wife's Timberlands are 20 years old and still holding up like they were new.

I thought I was buying my last pair of boots. They are warm and waterproof and fairly comfortable. They are heavy and bulky.  If you are going to work outside in the snow they would be ideal for that as long as you don't expect them to last more than a few seasons. They would be good for working at a ski resort as a lift operator or something.

My dad had some LL Bean Duck boots that lasted 30 years or more. I really thought these North Face boots would last a lot longer. How does the rubber/plastic lower portion crack in half? Are they biodegradable?

Background

Owned them for 7-8 years. Took them snowmobiling a couple of times in some really deep snow. The soles showed no signs of wear. They still looked brand new.