[Kelly_2000]

"My badly stated point was that looking for a reason why RNAP has the chemical structure it has is wasted effort. "

I cannot agree with that at all, otherwise the entire field of molecular-biology would be redundant. Please do not assume that much of what you consider "unknown" is indeed the case

[snarks_when_bored]

Molecular chemists and biologists try to determine the structures and functions of the molecules and molecular assemblages that they study. If you maintain that they're also trying to give reasons (in the sense of final causes) for their results, you'll have to give me some references.

[b_sharp]

I think that snarks_when_bored's 'why' was the intelligent intent 'why' not the 'what makes these work the way they do' why.