By your standard, only koryu and a handful of later arts qualify. Most arts that people consider 'martial' (meaning training for war) are not martial at all; the term was appropriated by westerners who brought the arts here.
Just a few arts off the top of my head that are still practiced primarily for
offensive/defensive combative skills.
Okinawan Goju-ryu karate
Uechi-ryu karate
hapkido (unless you'd care to argue this?)
Bajiquan
Krav Maga
Hakko-ryu jujutsu
Any iteration of the Vee-Jitsu systems
Plenty of the southeastern Asian systems including silat, kali, kun tao
Arnis
Arguably Jun Fan/Jeet Kune Do
While it is possible to 'do-ify' any martial art and make it more about mental and spiritual development, I don't think it inaccurate to say that some systems have traveled less on that path if at all.
And framing 'martial art' as training for war is playing word games IMO. The majority of the people here think of a martial art as a fighting system of some type, perhaps with a spiritual dimension added. It seems to me we should just go by the commonly used definition.
If you want to practice a modern martial art, get out of the dojo/dojang and either enlist or find someone to teach you military rifle use, including all of the marching and gun twirling (kata) and whatever hand to hand that soldiers are taught. I understand that anyone can go and take 'basic training' from groups that offer it as a course all its own and not as part of the military. That is martial art.
Does a modern martial art have to be about guns and rifles? I don't think so. Feet and hands remain relevant weapons for fighting, especially when the attacker is likewise unarmed. I believe styles like karate, jujutsu, TKD fit the definition of a fighting system just fine if trained as such.
And what arts have been altered for competition? Most of the supposedly altered arts were never 'martial' to begin with. There aren't possibly enough altered arts to account for the sport/art debate.
Karate in the main is an excellent example of where kata has been modified for tournament aesthetics. Dramatic pauses have been added along with crazy loud kiai. Stances have been deepened for visual flair, even hand movement have changed in certain cases.
And that's fine if this is the aspect one wishes to train in. On the other hand, training (dare I say it?) old school karate is very much still a possibility if one wants to and makes an effort to seek out qualified instruction from good lineage.
Then why give rebuttal to Glenn's comments in our conversation? It is the equivalent of me telling you that I am not bound by your definitions of KSD because I practice sword arts.
Because there is more than one shape and size of TKD. I've said before I wouldn't have batted an eye if KSD chose to call what he is doing TKD instead of KSD.