Except that it doesn't. The user who downloads pick-your-favorite-DVD-ripper doesn't even have to know that it contains code to remove CSS, they just download it and it works.
At the same time, DRM is costing them money. If I go to the store and buy a shiny plastic disc for $30 and take it home and it doesn't play because my $2000 TV from two years ago doesn't have HDCP version whatever, I am not going to go straight out and buy another $2000 TV. I am just going to spend my money on something other than plastic discs that won't play on my TV until the time comes when I would have replaced it anyway. And two months after that happens, someone breaks the new DRM and they come out with new content that won't play on my new TV.
The net result of DRM is to make piracy more convenient relative to purchasing. As far as I can tell its continued existence has only two causes: The first is the DRM snake oil salesmen bamboozling people into thinking it isn't a net negative, and the second (which I imagine is the real reason) is that it allows major content producers to better control content distribution channels and thereby exclude, tax or penalize smaller competitors. But that doesn't require the DRM to be effective in any way, it only requires the DMCA and lawsuits against anyone who attempts to challenge them in the market for content distribution.
No, it exists because it's usually a contractual obligation for licensing the content for distribution to at least make a token effort to protect content. That's really the biggest reason.
Source: I work at an entertainment company
Source: I work in my corner.
I have no need to lie nor any investment in being verifiably correct. My viewpoint is simply my own and carries its own validity according to however much people wish to believe me.
It makes it harder for a few people that crack it for fun, profit, kudos, whatever it is, but then it's exactly the same.
There is a reason for it, but mostly the reason is pretty misguided, and it absolutely does make the experience of the paying customer worse than that of the pirate.
You (and I) might think the whole think is a donkey circus that just ends up making things worse, but it's important to keep in mind that there is a reason for it, and it's not false consciousness on the part of the content owners, or magical pixie dust from DRM vendors.