Kylo obviously didn't like Luke's talking. Luke really hadn't quite known exactly how to approach him. If he'd said hello and talked, would it have made a difference? It was hard to say. Luke didn't have much time to think after the wrench was thrown. He dodged with his Force reflexes, then saw Kylo ignite his saber.
It was an unstable blade with a cracked hilt. It would surprise Luke if he had managed to avoid burning his fingers at one point or another.
Luke ignited his own saber to defend himself, the emerald blade a sharp contrast to the brilliant red. But although he was in a defensive position, he still tried to avoid a fight at all possible.
"I'm perfectly willing to back off and leave you in peace since that's what you seem to want." he said. "But, if you're intent on battling me, I won't hold back. Just don't underestimate me. I might not be as overconfident as my father, but I can certainly hold my own."