I think a parent has a responsibility in assisting a skilled player with getting exposure to the folks whose profession it is to objectively evaluate their abilities. Clearly, the player's abilities must stand on their own merit regardless. I think it's more accurate to say that a parent can and should help with 'exposure', while the player must 'promote' himself with his abilities on the field and his personal character/makeup. I think that good coaches can certainly help with that exposure, but the reality is these good people usually have day jobs, like teachers that are HS coaches, plus the responsibility of running an entire HS baseball program ... not to mention their own family lives ... so they're already really busy. It's certainly unfair to those coaches to expect them to carry that responsibility solely on their shoulders. One side benefit of private hitting/pitching instruction: these mentors are usually highly qualified to give you some objective measure of a kid's potential, good or bad, and many are pretty well connected with local colleges and pro scouts if they think a kid has a high ceiling.
If a kid is a once-a-decade phenomenon, sure, he'll get noticed taking out the trash. But there's a lot of really good players out there ... a lot ... that aren't necessarily the next Barry Bonds, so if you only played HS ball and did absolutely nothing else the other nine months of the year, you simply won't get the same exposure as a large number of the top 15%-20% tier of players out there ... there's just too many of them that the college recruiters and pro scouts have to wade through. It's no different than trying to find a job ... having a resume, using online resume publishing services, headhunters, contract recruiters, targeted marketing, etc., to help you find a job. You'll never find a job as the next VP of Finance at a Fortune 500 company by putting a hand painted sign in the window of your car and hope you pass a few CEOs on the freeway. You have to market yourself to the decision makers to have any chance at getting noticed, but you'd better be the real deal and able to deliver the goods once you're standing in their office.
Whether it's club teams, showcases, game videos, college camps, student-athelete marketing organizations like NCSA, or website profiles ... these are all just tools, venues, and mediums that simply help with exposure to the right kind of people ... evaluators and decision makers, but it's up to the player to make the most of those opportunities.