No it's not questionable. There's a strict definition of who was a Viking. As I previously tried to explain, the Vikings were Not an ethnic group but a kind of sea-faring raider. It was rather a kind of proffesion, not an ethnecity or nationality. The nordic term was "go in Viking". Far from every scandinavian was a Viking, so it's doubtful that most modern scandinavians (including myself) are descendants of Vikings, though I guess we in general are descendants from the different ethnic groups that produced the Vikings, like the Gutar, Götar, Svear, Däner (Danes), Norrmän (Norwegians) and others.
The Viking raids ended in the 11th century, so by then the Vikings were gone, since no one "Went in Viking" anymore. Instead the warriors of scandinavia was formed into armies under the kings. But it's wrong to say that the Vinkings stopped their operations because they became Christians; there were in fact lots of christian Vikings in the 11th century shortly before the raids decreased and halted.
/DK M