Let us consider a few different kinds of minds as legislators- that is, those who make the laws.
Lawyer: The technician of law. They first of all are most highly skilled in the current practice of law, the vocabulary of law, and, by thier very nature the most skilled in circumventing its intention. Much like how a computer programmer is probably better at hacking than anyone else in the room.
Author: Skilled in words, yes. Perhaps this means they will write clear laws, with meaning that is well-understood by all. However, a skilled lawyer will no doubt have the power to reinterpret this creatively. And a writer will most likely not be skilled in the existing practice of law, which eventually lead to contradictions with previous laws.
Engineer: Anyone who is skilled in the design of systems; for the purposes of law, I would consider a software engineer the same as an electrical one, or archetectual. If you found such a mind and taught it law, then you might get something pretty useful for legislation. You would, most likely, end up with a lawyer.
I feel that Lawyers make superior lawmakers, because they are the ones most skilled at defeating lawyers. A flaw with a lawyer-dominated government is that it creates a system of laws not open to negotiation or interpretation, especially once precident has been established. This is not a bad thing, so long as the laws are just; but if the lawmaking process is corrupted, which frankly is easier when naive lawmakers are in office, then iron-clad and evil laws will be made, a most negative turn of events.
I think that what we dislike of Lawyers as legislators is not their inherent lawyerness, but instead the inherent Legislationess.