Story highlights Maria Kang has been criticized for posting photo of herself in bra and shorts with her sons

Ruben Navarrette: Kang makes a good point about being healthy and staying fit

He says Americans need to talk to each other instead of getting personal and ugly

Navarrette: Kang isn't guilty of being a bully, but some of her critics are

Maria Kang likes a good workout. And she is getting one after a bunch of angry women turned her into a punching bag.

The 32-year-old Californian fitness enthusiast is under attack for posing for a cheeky photo and posting it on Facebook. The picture shows Kang -- who works out for 30 to 60 minutes per day, six days a week -- dressed in a workout bra and shorts that reveal an extremely toned body. She's surrounded by her three young sons -- now 1, 3 and 4. Plastered overhead is a simple but loaded question: " What's your excuse?

The photo went viral. It has more than 16 million views on Facebook and more than 12,000 comments. Most of the reaction has been positive; Kang estimates that the negative comments are outnumbered by the positive ones by a ratio of 7-to-1.

The photo is provocative. And it was meant to be.

Ruben Navarrette

But a lot of women out there were absolutely furious with Kang.

"You, as a woman, should be ashamed that you are furthering the downward spiral of how society views women, and how we women view ourselves," scolded one blogger.

Some call her obnoxious, a showoff, a bully shaming other women and worse.

What's worse? How about getting accused of being a "bad mother"? That's right. Some women had the nerve to insist that no one gets into this kind of shape without neglecting their children.

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Oh, don't go there. The last thing we need is another skirmish in the "mommy wars" where women compete to see whose maternal instincts are stronger.

"I did it because I knew it would wake people up," Kang told me in an interview while her sons clamored for their mom's attention in the background. "My intention was to inspire and motivate people to get healthy."

Her point: If a mom with three children can work out, eat healthy and stay fit, what excuse is there for the rest of us?

"It takes a lot of time to raise kids, but you have to also make time to take care of yourself," she said.

That isn't easy with Kang's schedule. She said she cares for her three boys without a nanny in addition to creating and running a nonprofit organization dedicated to helping people get fit

She wants Americans to lead a healthier lifestyle. Her crusade is personal. She saw her mother -- whom she describes as a 52-year-old saddled with the body of a 70-year-old -- battle diabetes in her 20s, a stroke in her 30s, and a heart attack and kidney transplant in her 40s. Her mom's health problems got Maria's attention, and the daughter -- who admits to being a chocolate lover and "sugarholic" -- aims to set a different example for her children.

Kang said she saw a column I'd written for CNN.com recently about so-called "fat letters" -- missives that schools send home to parents informing them their children are overweight.

I thought the letters were a bad idea. Kang disagrees.

"Parents play such an important role in teaching their kids to be active, to eat good food and stay fit," she said. "Not to diet. But to be healthy."

The "fat letters" got my attention for several reasons. As the father of two young girls, I worry that someday other girls -- what Hollywood has dubbed "Mean Girls" -- will lash out at them for their physical appearance.

As someone who is attacked by the left and the right, I worry that Americans have forgotten how to talk to one another without treating every annoyance or disagreement like a seek-and-destroy mission. And as someone who is in a profession that is supposed to be about defending the little guy, I worry that bullying has become the new normal and that everyone is so eager to play the victim that they miss the irony when they start victimizing others.

All these worries come together in the exasperating and yet empowering story of Maria Kang. It appears that the young mother was coming from a good place and that she wasn't out to pick on anyone.

Kang believes she is being a good mother, and she's not backing down. I asked her what this experience has taught her. For one thing, she said, she had no idea that mothers could be so competitive about mothering. She recalls the woman who wrote her an angry letter trying to one-up her, asking if she had ever started a business, gotten a Ph.D. or learned another language.

"There are a lot of people who don't take responsibility, who make excuses, who like to blame others," she said.

She's right about that. But enough about Washington.

After the government shutdown, a lot of Americans are talking about how Congress is broken.

True enough. But do you know what could really stand some repair? How Americans talk to each other, especially when they disagree. Our public dialogue has gotten personal and ugly.

Maybe it's the anonymity afforded by Twitter and other sites, where people can rip into one another in hurtful ways without revealing their identities. Or maybe it's just more evidence of what has been, over the last few decades, a gradual coarsening of the culture.

Whatever caused it, this much we know: Many Americans have forgotten their grandma's admonition that if they can't say anything nice about someone, they shouldn't say anything at all.

In the case of Kang, her critics should have said nothing at all.