Sadly, these trees were pruned improperly, and became high risk trees after the "tree undertakers" left.
There are published international tree pruning standards based on scientific research. These standards ensure that trees are pruned in such a way that they are healthier and safer. Ignoring these standards is not only bad tree care, but opens a company up to liability for failures. Remember the saying, "Ignorance of the law is no excuse"? It's the same principle.
Ask your tree care worker to explain the A 300 pruning standards. Their answer might be eye opening.
"Tree biomechanics incorporates biological study and engineering principles to understand how plant growth leads to the ability to withstand self imposed and externally applied loading events."
In a nutshell, it's the application of structural engineering principles to understand how and why trees deal with, and adapt to, loading forces (gravity, wind, ice, etc.), transfer of energy, and wood strength, with the goal of ensuring a tree is safer after a qualified Arborist cares for it. It takes specialized training that most tree workers do not have.
This image is of a long discredited form of pruning called "lion tailing". Tree researchers and capable Arborists have known this for decades. If your tree worker suggests your tree needs to be "thinned", or leaves your tree looking like this, then they are in violation of published tree pruning standards. This is wrong, and it makes your tree less healthy and at greater risk of failure.
Any tree company that approves of this type of work should be dismissed. They do not understand how and why trees grow. No matter how long they've been in business. They are tree "undertakers" and should not be allowed to touch living trees.