The CR9 crew probably never had a flight attendant or passenger get injured due to turbulence. Experience is the difference.
Once upon a time I was climbing out of a busy airport in IMC. I popped out between layers and saw a towering cumulus cloud with tops at about FL270. Our climb clearance was to FL260. I asked to continue the climb to FL280. Center wouldn't let me. I asked for 20 left. Center wouldn't let me. I asked for 20 right. Center wouldn't let me. And no, this wasn't painting on the radar, it was something that had to be seen to be avoided. I called the flight attendant to tell her to get in her jumpseat NOW. We hit the TC about half a minute later and got jarred into a 20 degree bank, experienced rapidly alternating positive and negative G's, and had the autopliot fail. She didn't make it back in time and tore her meniscus when the turbulence thrashed her into the galley cart. To her detriment she briefly argued with me when I told her to be seated: "but I'm in the middle of my service!".
We had to cancel the return flight because we didn't have a flight attendant that could walk. Even worse, she was out for months on OJI. My company had to pay contract maintenance to perform a severe turbulence inspection on the aircraft before it could fly again. I deviate around a lot of things now that I wouldn't have before. I give myself a lot of distance from the real nasty ones (20 NM or more). I probably annoy my flight attendants with how often I tell them to "stay in your seat until I give you the OK in the air". It's a personal goal of mine never to have that happen again. Next time, I won't let myself get boxed into a corner, I'll use emergency authority if need be to do what needs to be done to protect the people in back of the plane.
Towering Cumulus clouds are down right NASTY, and they don't necessarily have to be showing up on anyone's radar to be that way. So no, it doesn't really have anything to do with the airplanes themselves, it has to do with the pilots and their experience level. Freight guys: OK, boxes aren't going to bitch, but with passengers you have a plane load of liability that's just waiting for an excuse to SUE you and your company if you make a marginal decision. Maybe I'm a wuss but I'm afraid of getting fired for damaging an airplane, afraid of hurting people in the back, and am afraid of getting sued for everything I own for doing one of the above, however unintentional it might have been.