A better question would be, for example, "what career path in computer industry is most valuable?" Instead you picked a position of menial labor (roughly speaking) and proceeded from there. Sysadmins are janitors of server rooms; they fix old software, they talk to ISVs, they crawl under desks to connect cables, they fix broken computers... why in the world would you want your children to go into that job? Besides, IT departments are outsourced to India by thousands. Today's Internet allows Indians to manage your network from Bangalore, securely and reliably. You only need one local IT guy to, basically, replace the hardware when it fails. A monkey (untrained) can do that.
A bunch of earlier replies in this thread talk about Cisco and other router jockeys. Those jobs may be more lucrative... and at the same time they are more rare. How many companies you know that have a need for a Cisco router? If you just look around, most businesses (incl. small businesses) don't need any of that stuff even if you give it to them for free. I work in computer and hardware industry for a long time, and I can count all the Cisco routers that I saw on one finger of one hand. It's like going into general auto industry in expectation that you will be driving F-1 or Indy cars but getting an old pickup truck for delivery of groceries instead.
If I were to express an opinion, I would say that the best one can do in computer industry today is to become a developer. The absolute best if you have mastery of both hardware and software, and can do system design. That is not required, though. There is plenty of room for software development. You can write a program, post it on a Web site and collect revenue as it comes. The easiest, of course, is to write for smartphones - and that market is wide open and growing. Today's software for smartphones is laughable, compared to what it may be. But most is rushed to the market, with a generally correct idea that money today is better than more money tomorrow.
The reason why I think this is a better investment is because you as a programmer are not easily replaceable. You are an inventor, and inventors are unique. Sysadmins, on the other hand, can be replaced overnight. A sysadmin can't easily open a business and sell his product - he has no product, he has a service, and it's hard to sell it in the age of "clouds." A programmer can *always* set up a small business and code for fun and profit, be his own boss. A programmer is mobile, and if he is good he will be in demand. In the end, only the intellectual contribution is valuable in today's world. You can't beat Indians or Chinese on price, but you can invent better than they do, or invent in a way that US customers value more.
I had a conversation with a friend who is a small business owner just the other day, regarding clouds.
He said, (regarding the app we were discussing) "We'll just put it in the cloud."
I replied, "Good idea. How are you going to do that?"
He didn't have an answer. Sez me, that might be an interesting niche to fill. "Cloud technology" is great, but someone still needs to know how to use it AND be able to explain to businesses how they can safely and effectively leverage it.