Может быть, вы должны использовать «html5lib» вместо «html.parser», например:
from bs4 import BeautifulSoup
html="""
<div
class="ess-product-desc" ng-hide="currentView == 'detail' `&& deviceType=='mobile'"
ui-sref="detail({itemId: 'BWK6400', uom: 'CT', cm_sp:'', merchPreference:''})"
href="#/itemDetail?`itemId=BWK6400&uom=CT" aria-hidden="false">
<span>Center-Pull Hand Towels, 2-Ply, Perforated, 7 7/8 x 10, White, 600/RL, 6 RL/CT</span>
</div>
"""
soup = BeautifulSoup(html,"html5lib")
links = soup.findAll('div', attrs={'class': 'ess-product-desc'})
links[0].get("href")
вы получите:
'#/itemDetail?`itemId=BWK6400&uom=CT'