This isn't a rant I swear ... love DW or wipe yer arse with it I don't care ... to each their own. I just happen to like it and thought I'd post here about it.
@Rob S. I don't know what to say about your AW comment. The "sex" thing was really a very minor footnote to the game itself. Also sort of a prudish take given we all love Warhammer and I'm sure I don't need to explain how Slaanesh works
Kidding aside. The reason I like the system is it is free and open and not constrained with metric crap tons of rules and tables, so yes that is different from many old "core" systems. So right there I guess most "old school" gamers might decide to close the book and call it a day. No massive random tables ...anywhere ... so how can it be "old school" ... I can't answer that one honestly.
DW has a simple 2D6 mechanic which I love and in general the system is very open and flexible to allow for endless customization. One big reason I would happily use DW for a game set in the Warhammer universe is it is a dangerous game where PCs can easily die if they start kicking doors in and acting without thinking, etc. The DM has many mechanisms to advance their own "fronts" against the party which would be very useful in a Warhammer style game. The game is balanced heavily towards the DM like most old school RPGs. So overall DW has the old school dangerous feel to it that I fondly recall from 1st ed.
Player failure is a constant threat, they have to work together and not be bone headed if they want to succeed, otherwise, they die, fast ... to me very old school. WHFB, Red Box Basic D&D, etc. It is very easy to convert the bestiary of 1st ed. D&D, WHFB, etc. into DW so running old modules is easy.
DW does not hold the DMs hand and do everything for them, to run a good DW game it takes creativity, intelligence and a little work on the side. Using classic 1st ed. D&D modules and I would argue 1st ed. WHFRP modules as well is very easy with DW.
Again if players are being fools and kicking doors in modules like the Enemy Within, the Temple of Elemental Evil, etc. they will party wipe fast. There are plenty of ways to run a more RP centric game with DW, in fact I think the game is really not being played properly if that isn't the case. I feel that DW would do just fine for Warhammer based games when it comes to providing opportunity for dark fantasy and more RP centered game play. DW is a system that calls for DMs to be creative, to create custom moves and custom classes, it would be very easy to build any of the 1st/2nd ed. WHFRP character classes in DW.
As far as hack and slash goes I would argue that defacto most old school Fantasy RPGs are ultimately built for Hack and Slash, in fact I believe that the very concept of hack and slash is an OS concept. Personally in my several years of 1st ed. WHFB, then years of 2nd ed. play and decades of D&D most games ended up with some heavy hack and slash at times. Sure there might be political intrigue and nefarious sub-plots along the way ... but at the end of the day it boiled down to fun, gritty hack and slash combats. Not long drawn out "chess-match" combats (3.5/4e D&D did that though) but fast, eventful, dangerous combats that have meaning to the game where players can and will die if they aren't smart and a little lucky.
I think much of "old school" comes down to "I like my old stuff, it is awesome, not broken doesn't need to be fixed and I don't want to try new old school like stuff" and I hear that. For someone who can play the original games, who have groups who are willing to do so, etc. great, I envy you. I have no qualms with people who like their old stuff and have no desire to try new stuff, again I applaud and envy that and am trying to move in that direction myself.
I'd love to go back and play WHFRP 1st ed. though but that is going to be a long while off if ever ... I'm in a place where I am gaming with people in their mid-20s who are very casual gamers who look at those rulebooks and just laugh. So for me those systems aren't even an option , so I've had to look to easy and light systems that I can use to produce games that people will play yet have something of the feel and atmosphere that I want. Again each their own. DW is wildly popular right now for good reason, it is a great system, but again maybe not for everyone.
@ Galadrin -- Having read your post I would argue that in fact DW is set up well for a DM to run a game that is focused on the story, where they have the power to give the game meaning at every turn. I think DW is a bad game if the DM is not an old school storyteller. I think that there are so many elements of the game that actually facilitate really interesting game play. After having played 3.5/4e off and on for years and some retro-clone games I really much prefer DW to any of those options. I have found that DW facilitates story driven game play where "balance" isn't an issue, where there are real consequences to player actions and where there is a "real risk of failure" built into the game. So I think the Players learn that quickly, or they just run through characters incessantly and the DM gives up ... lol. I don't know if that is a good thing but luckily in our games that hasn't happened yet.
I will concede that much of what DW has to offer is it allows DMs to bring their own stuff to the table, it doesn't hold their hands and tell them how to do it step by step all the way, so I am sure that the experience with DW is quite variable and just depends on the DM and the group to a large extent.