Pruning should be done to enhance health, strength, vigor and appearance as well as to prevent limbs from interfering with houses, driveways, sidewalks and wires. If your tree has a few branch stubs after pruning, it has been badly pruned. If it looks like a hatrack, it has been horribly pruned. Whether you prune your own trees or have it done, you need to know good pruning from bad. The surest way to tell is by stubs.
Stubs are bad.
Also, a stub wound cannot close, and decay is almost sure to follow. As with most bad situations, the opposite is not always the cure. Flush cutting is a no-no. It removes the ring collar or ridge, at the branch base. The ring collar is the tree limb's natural foundation upon which wound closure is built.