The author's complaining about the marketing pages. Marketing pages are run by marketers, and marketers are trying to get your information. The real download pages (the ones in Google & Bing search results) are run by the technical teams who want to put the product in your hands.
Yes, the OP is complaining about marketing pages, because he doesn't want to deal with marketing! He wants the danged download!
If there's something wrong with that, go for it, but having to use Google to get to a download page from a vendor shouldn't be the 'solution'.
If you go to Shell.com to buy gas, you're going to be disappointed.
Should we have the same expectations for downloadable software that we do for gasoline (or any product that can't be downloaded or shipped)?
I say "no", but that's something we could disagree on.
Not strange at all. The #1 page is heavily SEOd by the marketing SEO teams. The technical download pages don't have the luxury of full time SEO teams.
What exactly is the purposes of a marketing team which prevents interested users from using your products?
There is no marketing to be done at that point - the market has already found you.
To the company there's absolutely a distinction. And to someone who's playing the long game there's absolutely a distinction. But those are red herrings. This decision's probably being made by someone who's got an annual performance review to worry about.