Unfortunately, they are short-lived species. Their limb structure makes them weak, and also susceptible to pests. My neighbors lost two limbs from theirs this afternoon, and it is debatable that they may need to remove the rest of the tree. That would be unfortunate, considering how much afternoon shade it provides to their home.
In the photos, you can see the damage done to the tree by the collapse of two large limbs. You can also get an idea of how the structure of the limbs allows water and dirt into the trunk, to weaken the limbs. That also lets insects in, and some of the photos show signs of woodpeckers drilling in to scavenge the tasty bugs. That can only compromise the structure further, as it allows more water to enter.
In the street shots, you can see my house on the left, with a Bradford Pear blooming in front. The photos show an intact trunk, with about 50 woodpecker holes. Actually, in an ice storm in 2002, we lost about 1/3 of that tree. Vigorous growth filled in the gap.
We used to have a second tree, just to the left of the existing one. The ice storm took about 70% of it down, and I removed it.
At that time, the trees were less than 10 years old.
My neighbors tree is less than 20 years old. It seems to me that a tree's life should be in the 75 to 200+ year range. It seems that a tree should offer shade and memories to multiple generations of homeowners.
But, we love our Bradford Pears for their blooms and shade and boisterous fall color. It just seems that we forget that we can lose them at any time, and that the 10 to 20 years we enjoy them might be better spent in the development and growth of a slower growing but longer lasting specimen.