There are as many kinds of contract lawyers as there are legal practices, and not all contract lawyers are mothers with young children. They want more freedom and flexibility to pursue other interests, such as spending more time with family, outside businesses or hobbies. Their legal skills offer an easy way to be mobile and make good money with low risk and overhead costs as compared to operating a small practice. Many simply don't like dealing directly with clients, and they know they will get paid for all the work they do when they work for law firms. Contract lawyers are now flourishing in the US, in a way that fits in with the whole small firm ecosystem.
Many small practices find contract lawyers fit beautifully into their business strategy.
And he works when and for whom he wants to work. A good client of my firm had an opportunity to enter into a joint venture to supply parts to a company in Canada. Fortunately, I was privileged to work with such an expert in the Seattle area. She was licensed to practice in both Canada and Washington State, with more than 15 years of experience in international commercial law. She accepts projects of this sort on a free-lance basis, which allows her time to write, teach and pursue another business.