They were defensive ammo, presumably intended to cut a channel that wouldn't close up so easily. They were occasionally called Dick Tracy bullets, after the Dick Tracy comic strip that illustrated gunshot wounds as perfectly cylindrical channels through the body. The design was originally intended for much larger projectiles of military use, and the intent was to provide much better exterior ballistic characteristics. The intent was achieved, even in the handgun projectiles. However, when PMC started making cartridges and selling them, they apparently didn't look quite closely enough at the ownership of the patent, which was held by the inventor, Abraham Flatau. When called on their error, they apparently didn't consider it economically feasible to pay royalties and keep on manufacturing and selling. I have no idea whether the main factor was the cost of royalties or the sales experience they had already had. It was posted here many years ago that they dumped a lot of bullets for a low price, and the poster got some of them.
I have a few boxes of .38 Spl, and consider them fine ammo, but they are very light (66 grains in .38 Spl), and pretty much require adjustable sights. I know the sight changes for my M19 and M66 (one full revolution up on the elevation screw of either 2.5"-bbl gun, from what I have it adjusted to for 110 grain .357 Federal ammo), but I haven't carried either in a while.
I would be interested in your .44 Spl ammo if you are looking to sell it, but I really don't know what stuff like that is going for these days.