You are kind of confusing pulldown and interlacing. If you "weave" two interlaced fields together (show them both at the same time) to get one progressive frame you *will* get nasty artifacts unless there is very little to no motion in the frame because you are combining two images that were recorded 1/60th of a second apart. You don't lose any spacial resolution but you do lose temporal resolution (60i down to 30p) and the image most likely looks like crap too boot.
You are confusing the stored format and the recording format as well. I'd wager that the vast majority of DVD content out there is 24p telecined. Yes, there are others that break the rules (animation in general is a pain, but can mostly be addressed with a good VFR encoder that can detect the frame pairs)... but the general rule is pretty straightforward. Who in the world actually shoots at 60i these days? My understanding is that both movie studios and TV studios have been using 24fps progressive cameras for decades.
And even as I say this, I will also say I /have/ run into 60i content... once. It was the end credits of an animated TV series where the translation team decided to run the end credits roll at 60i, despite everything else being run at 30 fps or lower. When you run into that, there is nothing you can do to restore the original image without doing some sort of blending, and it looks awful on newer TVs when you play back the DVD. But everything else I have ripped, old and new, has been progressive video that has been telecined or run at a VFR.
Heck, these days I just leave Handbrake's VFR option on and run sample encodes. Maybe 1% will not find the correct frame pairs, and those are situations where the DVD author is at fault (progressive source, bad choice of field layout in the encode). None of them have been live-action DVDs where a camera was used.
I'm not arguing that pure interlaced content isn't horrible to deinterlace... but I'm also saying that such content seems to be very rare and near nonexistant in the DVD realm. And it makes sense. Studios go back to their source footage. If it is film, it is progressive. If it is digital, it is progressive. They remaster the source before encoding it to the DVD.
In the DVD realm, interlacing is an artifact of an old standard, not a true representation of interlaced content. Put simply, they cheated to make DVD players that have to output at 60Hz cheaper to make.