Ironically, one of the reasons the article gave regarding why coaches yell at officials is simply because the coach is often significantly far away from the official, ergo requiring raising his/her voice just to get the attention of the official. To that, I must say, "Thank you, Captain Obvious."
But the article went on to discuss other more logical reasons why coaches yell. The problem is that the reasons and examples provided as to why the coaches yell were not fully acceptable or morally sound, even if they happen to be the truth.
First, the article mentions one of the reasons being that coaches have multiple responsibilities on a team, thereby not being able to follow the game as closely as an official may. That may be true, such as tending to injured players, determining when substitutes need to be deployed, or discussing strategy. But to play devil's advocate, is that really an acceptable excuse? Doesn't a good coach have the ability to follow the game and do all these other things?
A second reason, and one more damning and popularly used (especially at professional levels, which means lower levels mimic it), is to inspire a team. Many stories have been passed down that a large majority of arguments between managers and umpires in baseball are not actually about a disagreement over a call, but as a tactic to inspire a team to perform better. A coach who comes storming out of a dugout and starts going ballistic may actually be asking the umpire about where his dinner reservations are for that evening.
There are two problems with this method. First, it rarely works, especially at youth levels. Younger athletes tend to crawl back into a shell when this type of behavior is exhibited; they begin to play in fear of getting yelled at in a similar measure. Second, why does the official have to be subject to a misnomer from onlookers? The manager or coach may not actually be mad at the official, but the fans certainly can be deceived by this action. "If the manager of my team is mad, that gives me, the fan, the right to be mad!" Or, "Perhaps I should be mad too!"
One thing that is never acceptable is when a coach uses this method in a derogatory way against an official. It's bad enough when a coach puts on a mad display when he's not actually yelling at the official; but if the coach is actually criticizing the official to motivate his team, then that's grounds for ejection.
It comes down to this: officials shouldn't have to take abuse from coaches or anyone else. If a coach has to yell just to get the attention of the official due to physical distance, that's fine. But it makes zero sense to yell at an official for any other reason. And if you are someone who still wants to yell at an official, be prepared to face the consequences.