Words are regularly used incorrectly, even by the majority.
This is interesting and I would disagree as I believe language, especially spoken, takes care of itself, and cannot be used with the wrong meaning en masse.
If I can use Rocket League as an example. It has many different types of in-game purchases, both consumable and durable:
- cars (including themed car packs including goal explosions, skins etc) 0.99-3.99
- keys (used to unlock premium Rocket Pass and also unlock crates) 0.99-19.99 (RP is 9.99)
- tokens ("Items from the Esports Shop will require a new currency called Esports Tokens.") 0.99-19.99
- MLB fan packs (separate to all of the above) 2.99
That's four ways of buying solely cosmetic items of varying prices that have dramatic affects on the social aspect of the game, despite not changing the core solid values of Rocket League.
It's hard to ignore these micro-transactions even though you know exactly what you're getting.
So the term micro-transaction is quite broad and refers to anything bought in-game, consumable or durable, for any price, and it can often be undesirable for the consumer despite the core quality of a game.