If I understand correctly, there are a couple of ideas hiding in here.
One idea is that getting a weapon to 5 stars takes a lot of resources, and putting another 20,000 crowns into it isn't really that much. So do one Punch, and get a UV that is either slightly helpful or really helpful, and appreciate it for what it is. This view is healthful. Sure.
The other idea is to Punch items early --- at 2 stars, say --- and then decide their upgrade path based on the UV that you get. For example, if you get undead+4 on a 2-star Brandish, then upgrade it to an elemental option rather than a shadow option.
Back in the days of mist energy, a lot of players (myself included) would have multiple accounts, using all of that mist to mass-craft 2-star items, hoping to get good UVs, and upgrading to 3 stars accordingly. In fact, there were complaints that gunners and bombers were disadvantaged, because a lot of their weapon lines (e.g. alchemers) locked you into a particular damage type already at 2 stars. So yes, a lot of players agreed with you.
The problem is that damage bonuses are now so easy to get (Black Kat, Chaos, Barbarous Thorn Shield, etc.) that the monster-specific damage UVs on weapons are close to worthless. And player research suggests that damage UVs on armor and shields do almost nothing. So CTR, ASI, and status UVs are dramatically more valuable than damage UVs. So my advice to players is always:
* If you can buy a great UV from another player (e.g. CTR+4 on a 3-star Dark Briar Barrage or shock+4 on a 2-star Magic Cloak), then buy it and upgrade from there. Congratulations.
* Otherwise, use every one of your craftings to try to get great UVs. For example, if you have a 2-star Brandish with undead+4, don't keep that UV. Throw it out, just for the slim chance of getting CTR or ASI. If you make it to 5 stars without getting any great UVs (which is usually the case), then Punch from there. Or start again at 2 stars with a UV bought from another player.
You are right that there are a few special situations in which weapon damage UVs can be viewed as pretty good --- namely, when you use that weapon only on that one family. For example, fiend+4 on Dark Briar Barrage is good, if you use DBB only on piercing-vulnerable enemies, and you ignore beasts because they're too easy anyway.