The Warriors have taken ownership of LeBron James’ house, and they didn’t wait for him to move. They just stormed in, raided the refrigerator and staged a wild living-room party with about two dozen strangers.

What happened in Cleveland on Monday night wasn’t “just another game” — not for LeBron, the Cleveland Cavaliers, head coach David Blatt or the entire Eastern Conference. This was a nationally televised earth-shaker, a changing of the tide. It basically told the NBA that if the Warriors get through the Western Conference, it’s over. The Finals will be an afterthought.

Hold on a minute, you say. Things can change in radical fashion. In the glory days of Larry Bird and Magic Johnson, the Celtics obliterated the Lakers 148-114 in Game 1 of the 1985 Finals. “The Memorial Day Massacre,” they called it. Series over — except the Lakers won four of the next five for the title. The Knicks humiliated Michael Jordan’s Bulls by 37 points early in the 1992-93 season, but when the conference finals rolled around, it was Chicago in six.

There’s a common thread of superstardom — LeBron certainly belongs in that class — but such comparisons become irrelevant when you watch the Cavs play. They haven’t had a clear idea what they’re doing since the beleaguered Blatt took the job before last season. LeBron is the coach, in effect, and the offense invariably defaults to isolation plays, dreadfully far removed from the Warriors’ pristine selflessness and ball movement.

“It’s on Blatt to call a play to get the ball moving, but will the players even listen?” Jason Lloyd wrote on ohio.com. “They scrapped his system early last season and have been running what they want ever since.”

Blatt can’t be long for that town. He’s a worldly, engaging man who became a deeply respected coach throughout Europe, but here’s a question I’d pose to NBA players, executives or insiders: Who would you like to coach your team right now, Blatt or a guy who two years ago was playing for a Rec League team called Wonder Bread in Redondo Beach?

That’s right, you’d take Luke Walton. The man just knows things.

You have to figure Steve Kerr’s influence was vital in Cleveland. He was at the shootaround Monday morning, hitting one of his patented half-court shots for laughs, but he knew the team was slightly in tatters. That fierce dedication was missing, especially on the defensive end. Surely he reminded the players about their last appearance on that court — Game 6 of the Finals — and he probably used some forceful language to get the point across.

Once the game started, it took about five minutes to transport the Cavs right back to June. “This crowd is so quiet,” Chris Webber marveled on TNT, “it’s like they remember Game 6.”

The Warriors certainly did, crystallizing all of their values into “a championship response,” as guard Shaun Livingston put it, and taking a 43-point lead at one stage. As the Cavs’ Kyrie Irving properly concluded, “They came in and just kicked our ass.”

The Cavaliers have a couple of fatal flaws, at least when it comes to the really big games. They took on J.R. Smith last year, disregarding his history of suspensions, off-court incidents and utterly unreliable play. You can’t have someone like this. Just as the Clippers will regret signing Lance Stephenson and Josh Smith. Just as Dwight Howard, who never did get it, will let down the Houston Rockets in the end.

Sure enough, Smith showed up late Monday night for the Cavs’ biggest game of the season. He had a hot shooting streak, of course, but before long, he was ejected for a flagrant-2 foul on Harrison Barnes. Nice contribution. Vintage J.R.

Then there’s Kevin Love, who hasn’t fit into the Cavs’ offensive scheme since he joined the team. “It looks like he’s lost out there,” TNT analyst Kenny Smith said. Charles Barkley wondered why Love seems to settle for standing around the perimeter for a three-point shot opportunity that rarely comes.

“I think he likes standing out there shooting jumpers,” Shaquille O’Neal countered. “If you’re a great low-post player (that was Love’s reputation), run to the damn block and demand the ball.”

Love’s defense, meanwhile, is just laughably awful. The Warriors have burned him on pick-and-roll plays in both games this season (the Warriors won 89-83 on Christmas Day), and there are times when he actively flees a confrontation near the basket.

“Does KLove even try on D?” asked Al Harrington, the retired ex-Warriors forward/center, on Twitter.

To make matters worse, this was Love to reporters after the game: “We have a lot of things to get better at. That’s going to take a lot of guys looking themselves in the mirror, and it all starts with our leader (James) over there and dwindles on down.”

There’s a pointed finger with poor aim.

Throughout the Eastern Conference, a number of revitalized teams took heart from Monday night’s debacle. Realistically, LeBron can push his teammates past any of them in the heat of a playoff series. Not a single one of them, however, would have a chance against the Warriors.

Bruce Jenkins is a San Francisco Chronicle columnist. E-mail: bjenkins@sfchronicle.com Twitter: @Bruce_Jenkins1