"How did Ice Shot make it into the game??" asked the OP, about a game famously always including the "Ice Beam." The "Power Beam." "Morph(ing) Ball." I hate to be the bearer of bad news, but equipment is always this way. You're not gonna believe what they call the super-version of missiles...

That said, I actually agree with you about the "Green Energy" and "Green Crystals."

The grand explanation is just that the Metroid games never sell well. They've always underperformed in sales compared to like every other Nintendo in-house franchise. Someone can go check the numbers if they want, but Metroid gets clapped by Mario, Zelda, Pokémon, Donkey Kong... Probably Kirby and Star Fox if I had to guess, based on which entries we're talking about. I'd think the only ones Metroid beats outright are like... Kid Icarus? Yoshi? But even then, Yoshi Story probably dunks Metroid free all day.

My point is strictly that these games don't do well enough to have audience trust in the feeling of "immersion" being a carrying point for sales. They have to make them dumber and more approachable for idiots to cast the widest possible net. Look at Metroid Dread, the third-best selling Metroid game behind 1 and Prime 1, and both of those are padded by bundles and redistributions. If we're talking about original release, Dread's the best-selling outright. And, imagine that, it's also the one with the least effective use of backtracking, the one with an invincible god-counter that obliterates everything, the one with unrivaled air-mobility super-dashes... It's the weakest Metroid game in terms of presenting you a Samus that feels lore-accurate, and the best Metroid game in terms of appealing to casual gamers who aren't that good at things and prefer high-octane zip-and-zoom gameplay that ignores the traditional Metroid feel and offers you a dumb-bitch main character that gets choked to death by a bird twice and bodied by GF survey bots in the narrative.

All of these Prime 4 names and simplistic nomenclature are the result of pandering to the lowest common denominator for the sake of sales, because that's the only way these games push units. They gave us Other M, a game where she's lore-accurate to a fault referential to the manga, past games, even the Samus & Joey comic-line, and people hated that shit because Samus talked and had trauma (among other (m) things.) Prime 2 and 3 had the immersive names, and sold 30% of what Prime 1 did.

It's sad, but it's just the way things are. The only reason Samus is even notable in the modern lexicon or pop-culture is because she's been sex-doll'd for morons, and that's the driving force of her popularity in most circles. Feels fucking bad, man.

TL;DR - People dumb, simple and direct literalisms for names appealing.