"It is not true that if you devote most of your attention to marketing, [lawyering and administration] will suffer. It will simply mean that you need to hire or outsource."
Is Merenda's position—that "Marketing is job one. No clients, no law practice. If the new solo is good at marketing all other problems are eminently solvable"—transparently ridiculous? I don't know; it should be. But in case it's not, let's try concretizing the abstraction a bit and see what we get.
Fred is a new lawyer who went to law school because he wanted to practice law. In his third year he made a halfhearted effort to apply for jobs and got nowhere. He's okay with that—he'd just as soon work for himself, if he can, but he's a little scared. So when he gets admitted to practice, Fred forms "Lawyer Fred PC." The phone doesn't ring for a couple of weeks, so Fred gives some money to SPU ("Solo Practice University," where people who don't know how learn from people who can't), where Merenda tells him, "marketing is job one."
So Fred duly applies this gem of wisdom, and starts marketing himself. He takes out an ad on the back page of the local free classifieds, and spreads the word via social media at every opportunity: "Baby lawyer. No experience. Will work cheap."
"Affordable criminal lawyer. Free consultation." He gets a call.
Diane calls. She's an LPR with three US citizen kids, and she's facing felony drug charges. After making bail she can't afford the five grand or more that everyone else has quoted her. Fred'll take the case for a thousand dollars. Okay, Fred, you're hired.
Making marketing "job one" was an easy decision when there was no lawyering to do, and no administration, but now Fred comes to a choice point. Diane's case is going to take some work. Contrary to his marketing guru's suggestion, he can't outsource the alwyering. What is his first priority? Marketing himself or taking care of Diane—that is, lawyering?
If your answer isn't "lawyering," you definitely are not a lawyer.
Now suppose that Fred find some special marketing sauce that, despite his lack of experience, has the phone ringing off the hook so that he can afford to hire someone "highly qualified" to do the lawyering. Will he? How does Fred (who, as a new lawyer who has not made lawyering job one, is by definition not highly qualified) recognized, much less find and retain, someone highly qualified to represent the clients who thought they were hiring Fred?
And even if he can, is it ethical for him to foist the legal work off on others when the clients thought they were hiring him? There are people with law degrees who do this; some of them make lots of money, but they don't have the respect of their peers. They are marketers, not lawyers.
Mark Merenda thinks lawyers should be marketers. They shouldn't be. There's nothing wrong with being a marketer, but it's a waste of a perfectly good law degree.
Lawyers should be lawyers; lawyers should lawyer first. Only when the clients are taken care of and the bookkeeping is done should they turn their time toward marketing.
Anyone who says differently is selling something.