The second half of the problem is convincing advisors and advisory firms to provide a more forgiving and supportive career path for young people who may not be ready to bring in new business to a firm for many years.
"Some people won't admit that what they're really looking for is people to generate new business," said certified financial planner Jon Yankee, co-founder and chief financial officer of FJY Financial. "A 23-year-old won't be able to do that for you."
Yankee's firm, which now manages about $430 million in assets, doesn't compensate young associate advisors for bringing in new business in their first several years with the firm.
"We try to teach young people how to develop financial planning relationships," he said. "As they grow up, they'll develop their business."
Read MoreAdvisors slow to train successors
Other firms across distribution channels have also been changing their approaches with potential next-gen advisor candidates. The wirehouses, for example, have revamped their sink-or-swim training programs to offer more support for new hires and a longer learning curve.
At Merrill Lynch—the training ground for thousands of advisors, including many pioneers of the RIA industry—trainees at the firm now draw a salary for 43 months. They'll have to start producing new business before that, but they get a much more intensive financial training than they did in the past.