A destination wedding, to me, is a wedding where everyone has to travel to a place that the Happy Couple do not live, have never lived and have no real connection to (for that last, having had a nice vacation there once = has no real connection to). It's having a wedding in a particular place because the place seems like a good place to have a wedding, not because there is any connection to the Happy Couple there.
So, the wedding I attended that was in the HC's town, but everyone except two members of the wedding party who also lived there had to travel--not a destination wedding.
The wedding where I flew 2/3 of the way across the US because the bride was being married in her home town--not a destination wedding.
The wedding where I drove for three hours and the HC got married in the chapel of the college they attended--not a destination wedding. Even though the groom's family had to fly in from the opposite coast. The HC lived only an hour and a half from the college, and in my area, you will probably drive 45 minutes to an hour from the ceremony to the reception site, just because of traffic. But what makes it not a destination wedding to me is the ties that the couple had with their old college--this wasn't a random choice of "Oh, that would be a pretty place to have a wedding!" but more of a decision to get married where they met and spent several years together.
The wedding a friend had in Vegas--destination wedding. The HC hadn't lived there, all family members lived on the East Coast, and the reason they picked Vegas was, "Because it will be fun!"
There was a thread here a long time ago about someone from I think Philadelphia who had her wedding at a restaurant on the Jersey shore. The restaurant was owned by a relative, and she had spent all her summers as a child vacationing on the Jersey shore. It's probably about a 3 hour drive. Her family was giving her grief over her "destination" wedding, when really, the area was like a second home to her, and her family was accustomed to vacationing there. She did have a strong connection to the place, and that makes it not a destination wedding to me.