I do. Because they're not. They can be, and have successfully been, sued for a variety of reasons. They are also not immune to lawsuits stemming from gross negligence in supplying firearms.

The law is specifically in response to lawsuits specifically intended to do exactly what I said, bankrupt gun manufacturers. They sell a Constitutionally protected product with a wide variety of legal uses... but not to consumers. Firearms are sold to licensed dealers who then sell them retail.

There are arguments to be made for dealer liability, in very narrow circumstances.

And SCOTUS disagrees with you that 2A doesn't apply to what you're calling "weapons of war." There's a distinct legal difference between actual "weapons of war," such as the M16 and civilian variants such as the AR15. Legally distinct meaning SCOTUS has explicitly separated the two platforms in their official ruling. Going even further, SCOTUS explicitly considers tasers to be "in common use" with around 200,000 in civilian use and protected by the 2nd Amendment. There's quite a few more AR15s than that.

PLCAA is a good law that protects a controversial, but fundamentally legal and protected, industry from lawsuits intended specifically to damage the industry for existing.