[wahern]

I don't know the history, but some observations:

1) Some lawyers do sometimes charge flat fees for simple services. Indeed, even when lawyers charge by the hour, most services will be quoted as typically requiring X number of hours. In litigation it's common for lawyers to charge a fixed percentage of the recovered assets, and for it to be contingent on winning.

2) Lawyers can't guarantee outcomes. Sometimes the lawyer discovers some defect or problem that would require additional attention. Sometimes, especially in litigation or negotiation, the likelihood of achieving a particular result is a function of hours input, and even then it's continuously variable.

3) If a lawyer is losing money on a case he can't necessarily quit like the vendor of a normal service or good can and take a fixed loss. A lawyer has an ethical obligation and fiduciary duty to a client that can go far beyond that required by contract law.