Another way of looking at it, is Absorb Elements is too situational to be worth preparing, and PB uses per day of a situational ability is pretty close to "always on".
This is a legitimate argument. AE is costly to prepare, and even more costly to know for an AT or Ranger and it is rare you get the bonus damage out of it (because when you use it the enemy is usually immune). I have found myself in this dilima before because AE is really good when you need it, but costly to have on your list when you don't.
ATs are the worst because there are 3 1st level spells I really want (shield, find familiar, absorb elements) and I can only take 1.
My experience tells me either tables forget to roll consecration checks for minor damage, or they last about two rounds on average. And that's assuming you don't have some other spell you need to concentrate on. No concentration required is a huge boost, as is simply being not-a-spell. Which is not to say it is better than Hunters Mark - if you have spell slots (but are not a full caster) adding it to what you can cast is probably better, but if you don't have spell slots and do have the extra attack feature GCD is better. For example I could see a barbarian (not bear totem) picking it up to fill out resistances, and, as it's not a spell, you can activate the elemental damage whist raging. You could even use the ability on someone else's weapon - you can't do that with Hunters Mark!
The numbers work against this. To fail concentration you have to both get damaged and fail the save, and the save is easy more often than not. There is a lot of factors here obvioulsly, what are you fighting, what is your AC, what is your constitution, are you a front liner, but IME concentration generally lasts more than 2 turns.
I would argue because damage is higher, the difference with extra attack for a non-caster is actually is the reverse of your argument and tilts more in favor of the spell feat. The spell slots for a caster mean they can cast it more, but the guy without slots is less likely to be concentrating on something else. Since Hex does more damage, with extra attack this increases the per-turn damage difference in favor of the spell. From a math point of view, with extra attack even if you only get 2 turns out of hex, it is going to still be on par with 3 turns of damage from GMD. I think battles that last 3 turns or less are more common than battles that you lose concentration in 2 turns. So in general you are not going to lose anything and you have the opportunity for significantly more due to the longer duration.
Assuming we are talking about the magic initiate feat with hex. I think Hex is going to do more damage per day on average, what would really determine which feat is better is how you weigh the disadvantage from hex and the 2 warlock cantrips against what in play will usually be at-will elemental resistance as a reaction.
Generally, if they don't prepare it, it's because the don't want to be pushed into the designated healer role. Clerics and druids have plenty of spells they can prepare. But if you have it it sucks up your spell slots like nobody's business. "I lost 10 hp in that fight, can you top me up please?" Show me a wizard with Cure Wounds and I will show you a wizard who never gets to cast Fireball.
I would not say Clerics and Druids have plenty of spells. Certainly my clerics don't (although they are low level). Healing Word is our go to first level heal spell.
I think healing between battles usually comes from Paladins, Goodberrys or potions. Assuming there is no time for a short rest.
I think your comment about Wizards is off the mark. Consider a Divine Soul is considered one of the best sorcerer subclasses and it is because they get access to cleric spells. They still hurl plenty of damaging spells though. I think Cure Wounds makes sense for a wizard because they have no other healing option other than false life and false life will not bring up downed allies. That is where I think it would be used the most is to revive downed allies and get them back in the fight.
If you are really playing strict RAW, in tier 2 reviving downed allies is extremely important, both to keep them from making death saves and to get them back in the fight. When an ally goes down you need to get them back up even if as nothing more than another target for a couple enemy turns. That is generally more important from an action economy point of view than dealing damage is. A lot of DMs house rule this and give exhaustion if you are downed or some other mechanic to complicate this play style, but strict RAW this is important and it is what I think the most common use of cure wounds for a wizard or any other character (although as you mentioned healing word is better for this).
I am curious though about why you think it could make sense for a sorcerer in some cases but not a wizard?