I haven't taken a poll but I'm confident that the majority of hobbyist editors connect PC to TV via the camcorder, not the video card. It's invaluable in making quality judgements, particularly as real time editing explodes, with its down-rezzed playback windows. It's also faster and cheaper to export to VHS (vs DVD)during the process, to look at and listen to the developing project on your best equipment, which is probably not in the basement next to yor PC. Anyone with a VCR can benefit from tape made with the S-Video connection. Most don't own S-VHS decks but S-video playback is deck-agnostic, and just makes a slightly better image available to anyone with a VCR.
David Hurdon