Let's try to keep politics out of the discussion, & work on facts.
No other manufacturer or retailer of property is held accountable for what customers who buy their property do with it once it leaves the store. IIRC, cars kill something like 61 times the number of people that guns do, yet nobody is going after Ford or local dealers and howling to regulate cars more.
Be sure to vote in their poll:
As of 21:50 on 24OCT, it's running 55% saying no, gun stores are not accountable for crimes committed with the guns they sell.
From the comments, most people seem fairly reasonable, understanding that it's criminals who commit crimes, not their tools.