>>1121801they don't, really.
A bayonet is made for stabbing people - that severely impacts their cutting performance. Also, being purpose-built to be mounted on a rifle (like the AK bayonet is) doesn't do much good for ergonomics.
Pic related has great ergonomics (seriously, this has the most comfortable handle I have ever used), and for a general-purpose hunting/camping knife it is perfect.
I wouldn't recommend it, though, unless you have money to burn, as it's $240 - you can get a good hunting/camping knife for much closer to $100 or less. Some recommendations:
LTWK Bushcrafter HC
LTWG Genesis/GNS/Next Gen
ESEE 3 hm
ESEE RB3
TOPS Scandi Trekker
Falkniven F1
Cold Steel Master Hunter
Condor Bushlore
Mora Kansbol
Something from Helle, Ahti, Kauhavan Puukkopaja, etc.
In general - you want a 3-4 inch blade (5 at the outside), spear point or drop point (nessmuk is ok too), 1/8 inch thick, scandi or full flat grind, simple handle with no guard (or only the lower guard) and no deep finger groves. Again - see pic related - this handle is nothing short of amazing.
Also - you don't want your handle too long (the JX2 is borderline), or with any sort of "skullcrusher" grip - not if you like your own ribs (doing chest pull cuts will leave your ribs bruised if the handle is sticking out too much).
