Second, likewise, Apple sued every single wireless patent holders (eg, Nokia, Ericsson, Qualcomm, etc) to negotiate better licensing terms -- but, to be fair, it's not uncommon for other smartphone OEMs to do so in court.
Third, Apple's legal argument was always that Qualcomm's per-device (ie, final product) royalty basis licensing offer was not FRAND. Apple believes that the royalty should be based on the cost of Qualcomm's chips instead. But, of course, there is no legal basis or industry practice to support Apple's unfounded claim and, consequently, LOST EVERY lawsuit based on this claim for past 10+ years.
Fourth, "... then also to sue various downstream part contractors ..." No, you don't sue everyone in supply-chain. The wireless patent holders collect their royalty only once and at the top of the supply-chain, ie, smartphone OEMs, to maximize their profit. and that's been the industry practice for much of the past 25+ years (possibly even longer).
Fifth, "... it was untenable to have to source all of their LTE stuff from Qualcomm ..." Umm.. Stop, stop, stop!
So in conclusion, it's all about saving Apple's margin, that's all. I don't blame any company for trying to minize their cost, but the recent event with Qualcomm, ie, FTC's attack on Qualcomm with Apple orchestrating behind the curtain, was highly unethical and abuse of their political power.
PS. insulting languages removed