Your Playstyle is Not a Unique and Special Flower

I am seriously getting tired of seeing this sort of thing.

"Yeah, TH/SS are pretty good but it depends on your playstyle. In my group mostly we think they're kinda useless, since regular Terminators already have Power Fists and they get a gun as well. Isn't 5E all about cover saves?"

"Well sure mostly Pariahs are pretty bad, but it depends on your playstyle. Some people can do really well with them!"

"I know the so-called mathhammer says that vanilla Devastators with Lascannons aren't very good, but with my playstyle they really work. To each his own!"

"Rhinos may be a good way to move to objectives, but with my playstyle they aren't as useful, because I pick up the little figures and fly them around the battlefield yelling 'ZOOM! ZOOM! GO, MAH SPEHSS MAHRHEENS!' which can get them onto almost any objective pretty quick. It's all about the kind of army you run."

No. F&%# you all. Holes in all of you. Your "playstyle" does not invalidate the fundamental tactical, strategic, and numerical concepts of the game. Liking to assault does not change how often an Autocannon glances a Rhino. It does not change how hard (or easy) it is to contest an objective. It does not change the ability of a mobile army to defeat the opponent in detail. It is, at best, a subtle flavoring to the type of army you are most suited to run, nothing more.

Playstyles are a good way to choose which army to play. They are a good way to choose which build of an army best suits the things you enjoy doing. They do not rewrite the friggin' codex so that up is down and short is long. Some units are bad and will always be bad until the book is changed. Some units are good and will always be good until a new edition of the base book is released. It is only on the corner cases, the units that are on the edge of playable or are good but not great that change from army to army in how they rate against other choices. Your "playstyle" has nothing to do with that. A good army is a good army in the hands of any player, even if that player may not use it to its fullest due to inexperience or other factors.

If you like a unit, that is fine. You are allowed to like units even if they aren't good. I like Biovores, okay? And Ymgarl Genestealers, too. You don't have to pretend that you're picking optimal choices when in truth you're just picking the coolest models. And if someone comes along and demolishes your list on the internets and explains that it is bad and terrible and there are many, many ways to improve it and you don't have any real counter-arguments, don't just resort to "well, it fits my playstyle." F%$@ you, that's not an argument, that's a fallacy.

Alright, are we clear here? Playstyles govern the type of list you build. The type of list you build governs the choices you want for that list. The codex governs the choices available. Your playstyle touches upon which units are good in a list only in the most vaguely indirect way, in much the same way that Canada and China share are alike because they both border the Pacific Ocean.