Centuries later, after the reality of night attacks, house burnings and retaliatory murders had faded from consciousness, the deeds of the Border Reivers were romanticized in fiction. The Reiver started to be seen as a kind of Scottish cowboy figure. I'm fairly sure that the ordinary inhabitants of the Border would not have perceived them in such a generous way. If you have to live in a fortified tower just to keep from having your roof burned over your head by raiders in the middle of the night, then something is wrong.
At the same time, any simplistic condemnation of the Reivers would be equally wrong. Is it stupid to launch a retaliatory raid on an enemy family because they had previously raided mine? Maybe it is, if you take the big picture view. But anyone who took the big picture view back in the bad old days would have been easy prey for those who didn't. Retaliation has a law of its own- either you hit back, and you hit back hard, or you will be slaughtered like sheep.
The long-ago era of the Border Reivers is easy to romanticize, and it's just as easy to condemn, but both positions are luxuries of our own very different world. The Reivers were neither romantic heroes nor heartless monsters- just men attempting to survive and thrive under very harsh conditions.