It's a failure of technology when it's difficult to send ordinary-sized files like a few photos or a couple pages of documents. But it's a failure of people when they don't recognize the possibility that some types of data (video, large numbers of images, scientific research data, whole databases) simply can't be sent quickly, yet they fail to plan ahead to gain access. (I've also entirely skirted the issue of "some data should have its access restricted physically"...)
I disagree vehemently with that attitude, and I have to deal with it everyday. In my field, >50% of the data we receive is transferred by overnight courier of hard drives due to quantity of data. It's a crappy attitude to blame people for having to learn that, and in an ideal world we'd share it via access granted by email. People should not be blamed for not understanding that, our infrastructure should be blamed for not supporting 10Gb everywhere, and cheap access to 40Gb+ on long-distance connections.
Nothing is helped by blaming people, and relationships can be harmed by doing that. But we can change the technology.
As a side note, DVDs? Really? They're incredibly slow at data transfer once you have them in hand, the tiny size of a DVD requires tricky archive spanning methods, and optical discs are flaky technology all around. Hard drives or LTO-5/6 all the way.
Incidentally, it's not just about transfer speed. Sometimes people ask if you can e-mail something that has never been put on a computer, and would take weeks or months to scan in. Or sometimes they ask for access to information when access is very slow to set up due to security or privacy considerations. Or sometimes they ask for access to something that the boss needs to physically sign off on, after the boss has gone home for the day. This is only a problem if they've decided it's urgent to have it, and simply haven't thought ahead about how it might not necessarily be possible to get instant access to every piece of information that ever existed.
We can change technology. But we also need to retain the mindset of arranging access beforehand. It's not about "blaming", it's simply about encouraging people to understand what they're asking for and to make sure they get the access they need before they need it.
[As an aside, DVDs are just an example of "sometimes it's really freaking slow to download data" that somebody like my mom would get. An alternative way to phrase it would be "downloading that would be so slow, it'd be better to just have your friend bring her laptop over." I certainly don't intend to suggest a new industry standard.]
When somebody says, "can you email it to me" they mean, grant access to the data via their centralized messaging system, their email. There are many ways to make that happen, one of which is an attachment, another of which is linking to the content, but the key is to make sure that it's low friction and takes very little time or clicks to get access from the email.