But why?

Because telling people to "dopamine detox" implies that there is something fundamentally wrong with their brain chemistry. This can lead to maladaptive thinking, as discussed in this Harvard Health article.

Don't believe that people actually think this way? This is a link to a comment thread posted roughly 1 day ago. The comment thread shows someone who is self-medicating with a supplement that mimics L-Dopa, a medication that increases levels of dopamine in the brain. It is commonly used to treat Parkingson's disease. If taken recreationally, it will lead to serotonin depletion, anhedonia, and a bunch of other very nasty side effects.

So yes, I do think it warrants a change.