It never seemed like Nacho's hatred in Better Call Saul, as expressed in his final scene for Lalo, was very well motivated -- sure, Lalo is a Salamanca and an extremely bad guy, but frankly, Nacho except for his loyalty to his father and his distaste for involving "civilians" (at least killing them), was also pretty much a bad guy who sold drugs and associated with Tuco, which had to have meant he was involved in some terrible stuff, etc.
I do not think Lalo threatened Nacho's dad directly -- Hector did and Nacho sure did hate Hector and probably hated Fring -- actually, no probably about it. But why specifically Lalo?
Was Nacho trying to mislead the Salamancas and Bolsa by expressing false hatred, to try to shift suspicion from Fring, which was basically all he could hope for: Make Fring grateful enough to protect Nacho's dad after he was gone, which Mike would have helped to enforce.