I am almost certain they do it just to cause me Angst.
I have not read or noticed any difference in what type of primer is used.
I have a nice bag of them under the bench. Maybe load them if LPP get hard to find. Other than that I might trade to some one who likes to only stock one size pistol primmer.
Actually that's probably the reason we see them any way. Manufactures are trying to shave a couple cents off the manufacturing cost by ordering a bigger volume of SPP's
Usually if they do any thing thats not a performance or safety issue. it money related.