Because they buy it in large tubs at the auto parts store...usually called distributor point cam grease ((I know ..whats a distributor and what are points??) Hey, that's why the old black moly di-sulfide grease is so cheap these days.
Repackage it and charge 10 times what it's real street value.
Everybody does or has done this for years. I still have a little plastic syringe of something called "trigger job in a tube" (I think it was from Wilson Combat) I just refill it with the moly grease I have in a half pint tub from NAPA!!
I also have a bottle of "Buck Knife" honing oil from way back when. Dextron ATF that I paid about $5 a quart for!