It is not the tool that defines whether it be defensive or offensive, but rather the use to which it is put by the person employing it.I have a traditional/old world view or take on arms. An arm must be purpose built and used in warfare atleast once in history. Sword, Dirk, Certain Knives, Muskets, Sabres, Dagger, Modern Firearms, Flails, Medieval Mace, Warhammer, Spear, Bow, etc.
I still do not consider defense spray, Tasers, Stun Guns anything but a defense device.
Arms are strictly lethal for the most part. Defense devices not so much.
Criminals have used the three less lethal tools you mentioned in an offensive fashion - jus' sayin'.