Every time one ends up talking about which units are good and which ones are bad, there is always a minority who feels they need to proclaim the virtues of units that others see as terrible. Once in a long while they are right, but most of the time it's that strange somebody who must defend the honor of Swooping Hawks or Pariahs or what-have-you; units that are absolutely wretched, but somehow they still stand firmly behind.
Usually, the argument follow in sequence something like this:
"You just don't understand how to use them; they're very good at ______."
(Someone points out that another unit does the same job cheaper or more effectively.)
"Well, that's just one thing- they're very flexible and can handle any target I need."
(Someone points out that they have major limitations on use and are too expensive/fragile/etc to be good toolbox units.)
"Well, it depends on your army. I use them and they work for me."
This last argument is sheer nonsense. It's true- different armies do want different units, but that doesn't magically turn the world upside down so that bad units are good again. Winning a game with a unit does not make that unit good- if I get lucky, I can win a game with anything, and there will be times when all the stars align just so and conditions are perfect such that an otherwise-bad unit has the exact combination of qualities needed to be the holy savior of my entire army. But this doesn't happen often- that's why these units are considered bad.
If you're not looking to play competitively and don't care how well your units function (or are happy with how they function currently), that's fine. No one is here to force you to improve your army. But when you jump into a discussion and claim that something is a good/superior choice, you cannot then back out on the heels of "well, it's good enough." "Good enough" is a worthless phrase in competitive gaming. If there is a better option, you should be using that, not whatever "good enough" thing you have laying around.
Competitive play is about doing the best you can, not merely doing okay. If you're looking to improve, you have to be willing to ditch old habits and old setups that are merely passable in favor of others that are stronger; if you are constantly saying to yourself "Well, I win games with this army, so it must be good enough," you're not ever going to get any better. If you can't explain why or how your army works, chances are you don't fundamentally understand it yourself. If someone picks apart your list and tells you why it's bad and what can be done to improve it, saying "Well, it works for me" is the opposite of defending it- you are as much as admitting that you can't think of any kind of meaningful rebuttal to their arguments right then and there.
Good argument is founded on discussion. Discussion comes from sharing your ideas and thoughts with other people, and considering theirs in turn. If you are unwilling or unable to extend your half of the discussion- that is, to lay down your points and defend your side of the argument logically and intelligibly, you are not arguing well. Any time you default back to "Well, my experiences are different from yours so there's no way you can understand my position," you are arguing poorly. Don't sell your opponent short- and don't use your own inability to articulate your position as a cop-out.
