My overly simplistic, OCDness driven, Occums's Razor based opinion.
In terms of the playback chain...
There is no right or wrong because our perception of what we like is subjective and it is very likely that we are not all the same when it comes to this. This
just might be why different people prefer different equipment, different music and even different food. No matter how you look at it, our preferences in this hobby tend to be subjective. If this were not the case, we would all prefer the same equipment in terms of sound quality.
The correct differentiation is important. The "straight wire with gain" applies to basic electronic design where we want the closest resemblance of the of the output to the input, while moving or making the signal bigger or smaller. If we have this to start, as a base line, it can/may be acceptable to some and if not then the signal can be modified in whatever manner the listener prefers.
In terms of the signal in the realm of the electrical signal path this can range from changing the equipment (all the way down to the component level such as capacitors, transistors, vacuum tubes and so on), the most basic analog tone control to the most sophisticated DSP. In the physical realm, we can add in room treatment and things such a speaker placement and so on.
Again, based on the first line of this post, we like what we like and to complicate matters our preferences may change over time. As an example when I had my audio store way back, I sold a fair number of all in one compact stereo systems. Some of my customer remained happy with their initial purchase and some came back to upgrade.
Of course there is the recording chain, what ever that may be. Even for minimalist recording techniques of acoustic instruments, the
venue, and the type and placement of the microphone(s) will have an impact on the signal to be recorded among a lot of other things.
The simple answer is, nothing is perfect. Everything in the audio chain, physical to electronic, recording to playback will alter the signal, intentionally or unintentionally. And we are back to what any one person might prefer.
Debating this is just a strawman beating a dead horse.