There are pros and cons to that theory. Obviously the ideal is to recruit High School seniors and keep them around for four or five years and you eventually always have a strong Senior and Junior Class. But at the mid major level, that doesn't seem to be the answer for a lot of programs.
First of all, in today's society, kids want immediate gratification, so when they come to a school like UALR and don't get much playing time, they want to go where the grass is greener. So it's difficult to keep them until they develop into really good experienced players. Plus, talent evaluation of mid major prospects is more difficult. You can easily spot the stars, but we're not going to get many of them, so we deal more in potential, and you miss on more players.
A juco player is older and more mature, and has played at a higher level for usually two seasons, so your evaluation is probably more accurate. Plus, from a shooting perspective, since the high school three point arc is shorter than the college line now, it's hard to really know how good a shooter will be in college, but you can evaluate a juco shooter, since he's shooting from the same distance.
And lastly, you only have to worry about keeping a juco for two seasons, which is a lot easier than keeping a player for four or five seasons. And most mid major coaches, if they are smart, aren't looking four years out. They know they need to win "this year", because if they don't, they won't be around to coach those four or five year players, so it's important they win now and let next year take care of itself. And if they do win big, they might have a bigger job next year. So it's a matter of self preservation. I can't criticize Brady for trying to give himself what he believes is the best chance to win right now. Of course if a coach has a lifetime contract, he can do whatever he wants with impunity!