http://techcrunch.com/2014/03/21/lawyer-disrupt-thyself/
I don't think they're fictions insofar as lawyers (and laws) command a unique place in our society that other industry inputs don't. Insofar as lawyers have the ability and the incentive to prevent sweeping changes to their industry, the guild mentality seems very real to me.
I take your point though: smaller firms are very willing to make technology changes to find themselves new competitive advantages. Here's hoping smaller firms like yours (and mine) keep nipping away at those monstrous firms =D. FWIW, I have not had positive experiences when dealing with them...
I'm trying to think of a concrete example of protectionism keeping out new technology, and frankly I'm at a loss. I don't think it squares with the economics. Clients these days come with a budget in mind. If a law firm can do the work with say half as many billable hours by using technology, they can bid to do the work for a fixed fee 25% below the market rate, and then pocket the difference. It'd be a no brainer, if that technology existed. Instead, more often you see firms agreeing to a budget cap and just eating hours billed over the cap.
And the government and guild protections are fictions. I work at a small boutique that would love to be able to take bigger cases away from big white shoe firms by leveraging technology. We're not going to leave money on the table right now because of some abstract loyalty to the "guild." If the technology existed, we would use it. So would everyone else. The legal industry is extremely competitive. There are hundreds of large business law firms in the country. Way too many to keep up some artificial convention not go adopt new technology that works.