Looking at this thread nobody said they were ready to pay $100 -$150 dollars for the software engineers are not free or cheap. Mostly oceanic engineer is pc engineer only since Mac had les then 2% market share when dive manufacture got into the download business.
Actually, in practice, retail price really is closer to free than $100-$150. Divelog is $30 with a 30-day trial. Macdive is free with a requested donation. There are some other older efforts as well, generally also open source (read free or low-cost).
There is a community of diver/engineers more than happy to write the software and make it widely available. The problem is that the manufacturers hide the download protocols so that in addition to the effort of application design and coding, the protocol must first be reverse engineered. And then the manufacturers give away their software, but leave it buggy and feature-poor and poorly supported.
There has been a lot of speculation on why; for Oceanic the best guesses I've seen are that they originally farmed the s/w out to a third-party but at a cost of making that third party exclusive owner of the protocol spec.
Suunto seems to use the closed protocol to create an artificial marketing differential over the low-end Gekko model (no download by Suunto s/w, but it's there with any third part s/w).
Read this and other related threads; the argument that this is a straight engineering cost recovery issue doesn't hold up; the manufacturers give their s/w away, presumably to sell computers (or maybe cables), and others are standing in line to do the same, for Macs, PCs, linux, iPhones, etc. etc.. If the manufacturers opened up the protocols and let third parties write the s/w, they would presumably actually save money, sell more computers, and their customers would get a better s/w product.
One more thing most people forgot the download was for DAN (Diver Alert Network) so they could look at people dive profiles.
DAN Divers Alert Network : Medical Research : Project Dive Exploration : Participate
I don't read that link with that interpretation. It looks like DAN is leveraging already-existing download capabilities, added by the manufacturers to provide features their customers want. I don't see anything here that suggests the manufacturers added this to support DAN's PDE. In fact, this thread being mainly about Oceanic products, note that Oceanic doesn't even directly support PDE, there's some additional data processing required to make Oceanic data useful to PDE. Which makes it pretty clear which came first.