I realize the question can be considered inflammatory - use the latter wording (wasteful) if it helps...  When I learned (taught myself) to cook and first figured out that meat does indeed have a flavor of its own, I struggled and finally learned how to retain those flavors - everything from making broth with bones to slow-cooking to release natural fats and connective tissues. However, a friend uses chicken that is "parboiled" in many dishes, and this seems quite wasteful to me.  I understand that parboiling can be done to reduce cooking time. However, help me either understand this preparation mentality, or explain to them how to do things better...  My friend puts chicken breasts into a ~3-6 qt saucepan on the stove in warm water, turning the burner to high. After the water is boiling, heat is reduced to medium (50%), and left to boil for 30 minutes or so. The pot is drained and the chicken either shredded or cubed for use in a pulled-chicken or similar dish (perhaps enchiladas or similar). The chicken is fully cooked, but usually lacks taste - as I figure, it was all boiled out of the chicken during cooking.  This seems wasteful (stupid) to me - as the friend often goes through extra effort to use high quality ingredients, spices, seasonings, fresh herbs, and selects healthier meals. The only potential gain I see to preparing the chicken in this fashion is that the cooking can be done relatively unsupervised (plop chicken in, adjust heat once, and walk away). However, taste is lost when instead there certainly must be a better way to prepare the chicken. Perhaps in the case of the aforementioned enchiladas, the chicken could be placed in a skillet, half-covered with a mix of enchilada sauce and water, covered and cooked on medium for just about the same amount of time. This would flavor the chicken more instead of removing the flavor, and with little additional touch-time.  This friend comes from a background of much prepared food and poor cooking habits growing up, but has taken the time to advance their skills greatly in other culinary areas aside from meat preparation. I'd like to encourage them with evidence (and gentle pressure if necessary) to improve this facet of their cooking as well. Perhaps they are used to canned chicken which is precooked, as I believe this method for cooking chicken originated out of one snack-dip-related dish, which was a staple for them previously.  Bonus points: is this technique even parboiling? Above-quoted answers cite parboiling to be boiling to speed-up preparation of the parboiled food, but don't mention the intention of completely cooking it. 
I do this all the time when there's a good sale on chicken ... but I start them in boiling water, then turn the pot to low and let it simmer so I don't overcook it.  (and it'd be considered poaching, not parboiling)  I'll then bag it up and freeze it.  Although I typically also use the liquid to make stock when the chicken was bone-in.  It's a convenience thing.  Starting from pre-cooked chicken, I can make many dishes in under 20 minutes.  When I'm cooking for myself, and not trying to impress anyone, it's really not a big deal.  Most people are impressed that I can cook at all, much less do it well.  And if I can make it look easy, and get dinner out quickly, that's even better.  Poaching and freezing also means that I waste less food, as when I have some plans unexpectedly come up, I don't forget that I have a pack of chicken in the fridge, and find it's gone off by the time I've remembered it.  (or finally gotten back home and recovered enough to cook again)  There are some things that you can do to improve the poached meat.  Flavorful sauces is one.  Cooking thighs or dark meat is even better.  (and it's so much easier to debone when it's poached vs. raw).  You can also put some oil in a pan and give it a bit of a sear as you heat it back up.  I view your attitude as being like a new manager who decides to make changes in their first week without actually knowing what's going on.  Ask your friend why they do it this way, and you might come away enlightened.    You may also want to look up the term 'satisfice'.  I started doing this as a grad student -- there's no way I was going to spend an hour cooking a meal when I got home after a full day of work & night classes.  But it was either taking shortcuts like this, surviving off sandwiches or prepared foods like microwave burritos. 