I am more than okay sacrificing the video for image quality and buying that separately. They are for completely different products, the video not being as important. Just for some side Vlogging.
If all you're doing is short interview-style segments, where you can fix the camera on a tripod and the subjects aren't moving, the DSLR will actually be just fine. You'll need some improvement to the audio, such as a shotgun mic or a lavalier mic. The camera's onboard mic will be pretty lousy. And, DSLRs have an artificial constraint on the size/length of video clips (4GB or 29:59), so you have to shoot in relatively short clips and patch them together later in editing - though the Magic Lantern firmware will help circumvent that.
If you're carrying the camera around and the subjects are moving, the DSLR becomes much more difficult to use. That's when a dedicated video camera is much more handy.