J. S. Bach was also being extremely logical (rather than emotional) about music - he devoted his whole life in creating cleaver patterns in contrapuntal pieces.
I think you may just be alien to the manner of thinking in remote centuries: there was a general notion that things worth doing were worth doing well, even if you were emotional about them. Part of the reason was that there was a fierce competition among people in the creative business (and a rather limited number of employment positions) and you did not expect to be living from royalties for the rest of your life once you managed to create one item of exceptional quality.
The last completed major vocal work of Bach was the Mass in B minor. It was a Great Catholic Mass of old rite. Its instrumentation was too large for private performances, Bach himself was Protestant, and it being of old rite means that it was unperformable even in Catholic churches. It's deeply religious and stirring, masterfully composed and assembled, taking a lot of work at what happened to be the final years of Bach's life.
It was not written for Bach's world, not sellable (and there is no indication he tried to sell), and unperformable because of a variety of reasons. It actually saw its first full performance after Bach had been longer dead than he had been alive.
Stating that Bach was "logical rather than emotional about music" because his compositions are masterfully executed to fill out the framework of harmonic theory is not doing a lot of his work justice just because he did not have a priority for creating happy catchy sound bits.
It is not clear why you even mention Bach: he is not a classical composer but belongs to the Baroque period. Bach actually takes a lot of liberties with harmonic rules, breaking them rather unceremoniously and judiciously in order to cram more melodic and harmonic material and continuity into his compositions than could otherwise be accommodated.
Baroque music was on its way out in public favor, but while the reception of it dwindled, the fascination of the coming Romantic era composers with what Bach cemented kept them more obsessed with the traditional rules of harmony (and with Bach's work) than their audience.