I always pack up and get going. I don't like riding in the rain, probably the thing I like least about touring. But like hills or wind it is part of the stuff one has to do. It may help to have lived somewhere with a lot of rain where not riding in the rain = not riding. I got a year of the Irish climbing scene in the 70s, and while climbing in the rain isn't as bad as camping and riding, it is maybe more daunting to those not doing it.

I also agree that playing the weather forecast may cause one to be endlessly delayed as the system sits in place. However, I might not start a trip if the forecast was bad and the trip was local.

One reason not to stay in camp is because there isn't much to do. If that were not the case, either because of location or abundant wifi, that might make a difference.