Well there are different reasons for heavy or light bullets in a given caliber, most of which have been touched on here.
Michael hits a home run with the only gun and only mold.
.....
Hard to make a blanket assertion and cover everything, so yeah, different applications, different loads. "It depends" comes along every time we try to make a rule.
As for the one gun, one mould thing, I'm set up for that. I have several 358 moulds that I like, but also have a "succession plan," or maybe it's a REgression plan. Saving the really long story, the 3", 5-shot 357 will be the absolute last to go, if things should go that way. I'm not talking conspiracies, zombie take-overs or anything like that, but real-world things like what will MY economy look like in five years, ten years? WilI l be able to take care of my property or have to move to a smaller place?
The ONE mould that I would take is a NOE 360-180 WFN, plain-based to weigh 187 grains. It's a bell-ringer/vermin-buster/squirrel load/... in the suppressed 357 carbine and can be loaded to 1800 fps therein as well, if needed. In the 3" revolver, I can push it slow with a pinch of powder and still have adequate mass to effect good momentum/penetration without exploding my eardrums and lighting up the night. Small game to deer, personal defense.
@Glen wrote a neat article on the Lyman 215 grain SWC along these lines.
I'll take the momentum offered by the greater mass over trying to hit 1400 fps with a 125 JHP any day for about any purpose myself. 125 JHPs in a 3" revolver are nothing like 125 JHPs in a 6" revolver, so the slower 180s come in handy. Not criticizing the 125s at high velocity at all here - just that they won't do for me all I need done if I can only have ONE.
Is it folly to shoot nothing but 180s in a short 357 for everything all the time? Sure. I shoot other stuff to conserve lead, but my go-to, last-ditch will be the "heavy" all the way.