GLENDALE, Ariz. — Yeah, that 49ers performance set the franchise back a good 10 years.

Sunday’s 47-7 defeat to the Arizona Cardinals signaled the dog years are officially back. Including last week’s chin-check at Pittsburgh, the 49ers have lost their last two games by a combined 65 points. They’ve been humiliated by good-but-beatable teams, both minus key players.

The proud franchise, which was just in the Super Bowl in 2013, has hit rock bottom.

“It’s an embarrassing feeling,” linebacker Ahmad Brooks said. “I don’t think I ever lost a game by 40 points. I’m smiling, but deep down inside it hurts.”

It was jarring to watch. The 49ers completely imploded Sunday right before our eyes. But let’s not act as if this is a shocker.

The season-opening home win over Minnesota was the fluke. What we’ve seen the last two weeks, that’s reality. The 49ers are not good. They aren’t good enough to hang with really good teams. And we knew this was coming, even if denial won out for a spell.

It was much more likely the 49ers would be scrubs than serious contenders.

What just happened to the beloved Bay Area franchise was in the stars. The deterioration has been underway for years. All the drama. All the misfortune. All the bad decisions.

This season is like bad truck stop coffee that’s been on the burner for a while. It’s your fault if you expected gourmet. The smart move would’ve been to brace for disgusting.

Sunday, the 49ers fans watching that performance probably looked as if they’d just sipped a cup of burned joe from a musty rest stop. Because the 49ers were disgusting Sunday.

Yes, quarterback Colin Kaepernick will get most of the venom after being intercepted four times, twice for touchdowns. He certainly earned it as he uncorked some throws you just don’t see at this level.

But Kaepernick isn’t alone in the mess. The 49ers have several donkeys on which to pin the tail, and the place to start is at the top.

Yes, this is all fruit from a poisonous tree. This is the produce from two years of mismanagement. Trickle down NFL economics.

The 49ers ousted a good coach in a seedy manner, then went on a campaign of spin — “mutual parting of ways” — instead of being upfront and transparent.

A lack of accountability trickles down.

The 49ers hired a head coach as if this team were a humming machine and any competent plug-in would do. On the contrary, this season was always headed for disaster. The defense lost several key players. The rest of the league is onto the quarterback’s weaknesses. The offensive line is a mess. Several draft picks from the last couple years aren’t panning out.

The meteor had been making its way to Santa Clara. The 49ers needed a specialist to redirect that thing.

Instead, they hired a guy who’d never even been a coordinator at this level. They selected based on emotion instead of expertise.

Truth is, the task at hand is above coach Jim Tomsula’s pay grade. He’s warring against powers that were working against him before he signed the contract. And he has no experience to handle this. He was set up to fail.

And now the 49ers need some incredible leadership to guide them through this merciless salvage mission. Just as they needed the same kind of leadership to handle the coaching change. And the rash of arrests. And the issues at Levi Stadium.

After Sunday’s blowout, Tomsula said they had a good week of practice, and that the team was prepared. This whole 40-point destruction thing seemed to be a surprise to him.

“We’ve got to play better defense,” Tomsula said when asked his concerns about his defense. “We’ve got to play better offense, play better special teams. Play better everything.”

Poor vision trickles down.

The 49ers are now grasping for answers. They’re not just overmatched but are being outworked and appear to be quitting.

Even the coaching staff could be accused of loafing Sunday. The game plans seem to highlight their players’ weaknesses instead of their strengths. The scheme is predictable for fans, so you know opposing coaches are all over it.

The offense is built around power running even though the offensive line doesn’t get much push, and the passivity of the play calling is allowing opposing defenses to tee off.

Down 21, the 49ers punted on fourth and 2. Down 28, and facing a third and 20, they ran a 2-yard out pattern to Anquan Boldin. After Kaepernick threw his second interception, the 49ers willingly became one-dimensional and stopped passing.

It felt as though they’d quit. If Kaepernick can’t run the offense they think will win, take him out. But as long as he is in there, they should be calling plays to win the game, not to avoid mistakes. And losing teams at least need to go down swinging, not try to mitigate the damage.

On defense, they played soft in coverage, relying on zone defense. Of course, that scheme relies on meticulous execution and discipline — not usually the trademarks of a unit with so much youth and newness.

Several times, the 49ers had a linebacker start on Larry Fitzgerald, an All-Pro receiver. That linebacker would then release Fitzgerald to a teammate, and the teammate wasn’t there.

Fitzgerald finished with 134 yards receiving and two touchdowns. Once, linebacker NaVorro Bowman threw his hands up in confusion and frustration while chasing down Fitzgerald.

Undoubtedly, millions of 49ers fans were throwing their hands up with Bowman. Not because the 49ers lost, but because they looked so lost while losing.

There was some hope things would be different. If everything broke right, the 49ers could’ve surprised some people. They could’ve looked like a team on the ascent that just needed time to jell.

But three weeks in, this season is circling the drain. And this could’ve been expected. Because dysfunction trickles down.

Contact Marcus Thompson II at mthomps2@bayareanewsgroup.com. Follow him of Twitter at twitter.com/ThompsonScribe.