To explain in a different way: There are two points that are key to understand.  
First of all, there exist pains locations, reactions and types that have not been understood by western medicine. Simply because they have not been listed in your A&P (or biochemistry texts) does not mean they don’t exist. For those that have paid attention to what you clients report, have read Simmons & Travell, or both, you will notice that there are (painful) sensations that are not according to anatomical reason. If you pay attention long enough, you will find that there are both regular and very unique ones. On top of this, if you listen (and notice as you receive) you will learn that there are also different types of pain: some are routine, others are unique. For instance, the Liver meridian is sharp pain, somewhat crippling, not-fun, whereas pressure on the Gall Bladder usually feels strong, good.  
Secondly, in order to communicate we have to assign names to things. Calling it a thing-a-majig, Dodad, etc. isn’t really helpful. It is also important to remember that a thing is what it is, regardless of the name. As Richard Feynman pointed wrote about learning from his father: whether you call it a Mariposa, a Butterfly, a Farfalla, or a Schmetterling, it’s all the same. You can call them Trigger Points, or Weird Painful Spots, it doesn’t matter, except that in the former we have no F’in clue what you are talking about. Sometimes a lousy name sticks and becomes permanent, like x-ray (x being the normal first mathematical variable- they were playing with an unknown “ray of energy” so they called it x (x-ray) 
If you actually open up Simmons’ and Travell’s books you will understand why they picked the names they did. If you read the first two chapter you will not only learn their technique and the results they achieved but also the limits and what else they discovered.  
So yes, I use Trigger Points, for it’s the easiest way to communicate. I have read many books with an open mind. While Trigger Points are not a cure-all, they are just another tool for me to help people. Like a Phillips screwdriver or Fireman’s (fire hydrant) wrench, it’s just another tool, and allows me to solve problems when I need something more than “just a hammer”, as the world isn’t just “nails”.