Inferior options exist because they logically should in the setting. Some things are more effective than others, and if you don't like inferior choices (and better ones are available; availability is always an important consideration) then take them.
Then perhaps inferior options should be labeled as such, maybe? It's probably not as necessary these days- the internet will quickly explain what the good and bad options are for players, unlike the dark days of AD&D when I was left to figure it out myself.
Of course, if people are informed about the value of options, it feels like inferior options are a waste of ink on a page that could have been used for something else, but I don't completely disagree with your stance- if the game didn't have stats for greatclubs or knives, on the assumption that no one would ever wish to use one, that can certainly create issues- would that mean no one in the world uses these weapons? Would they simply not exist?
Really, my issue is less that inferior options exist, but that some aren't made clear. To go back to my 2e days, no one told me that dual wielding was the superior fighting style to anything else you could be doing, or that I shouldn't want to use a greatsword when the long sword existed.*
*To be clear, there are circumstances where this isn't true. If you're fighting a giant and you don't have, say, exceptional strength or weapon specialization, the 3d6 damage of the greatsword is superior to the Large-sized damage of two swords. Or if your DM is taking weapon reach into account, which can offset the slower speed factor of a zweihander, etc..
Many would chalk this up as a learning moment, leading to better "skilled play" on the part of the player. And there's something to be said for that, but many are the times I hear DM's sigh or shake their fists at "damn dirty optimizers" ruining the game, as if this wasn't an inevitable consquence.
It's great if the DM steps in- I remember someone whose character was a former tavern bouncer, so they wanted to use a club. The DM pointed out that clubs weren't great weapons.
"That's fine, I want to use a club."
"Well, why don't we say you use a 'heavy club', that has the stats of a warhammer?"**
**I'm fully aware, of course, that using a d6 instead of a d8 weapon is far from the end of the world. 1 point of damage won't make or break a character (one would hope). But I see this as going both ways. If there really isn't a big difference between a club and a warhammer, then having to have separate stats for "one-handed bludgeoning weapon" in the system feels even less necessary.
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Tying all this back into the weapon breakage discussion, there is, of course, another reason to use a weapon that is inferior on paper. I was just reminded of this:
Back in an early 3e game, the DM's house rules mentioned weapon breakage, and his NPC's often attempted to sunder weapons. When the first session came, one of the players showed up with a Barbarian he called Jaxsen. Jaxsen's weapon of choice was a staff. Everyone thought this was very odd, but Jaxsen's genius became apparent.
Staves could be used as double weapons, or as two handed weapons, both functions that really leveraged the high Strength of a raging Barbarian. Better yet, by the rules, they were cheap. So cheap, in fact, that they had a cost of 0 gp, since the rules assumed you could easily find a usable staff in most areas. Because of this, even if asked to Craft a staff, the DC was 0 since it had no gp value (bit of an oversight, I'll admit).
Thus, Jaxsen carried more than one staff, and if it was broken, he'd quickly produce another.
Then at some point, Jaxsen took a Druid level and purchased a Wand of
shillelagh, further allowing him to show that his inferior choice needn't be one.
