[mnicole]

If you don't, someone else will, and they might be even less ethical than you are. Additionally, like codegeek said, you may be shutting one person out, but you're opening the door for another or making them step up their game. There's also no reason to feel guilty because someone didn't do enough research into their profession's outlook. I saw first-hand how co-workers struggled with making the switch from desktop publishing to web; it was awful for them, but it would have been worse for everyone if the web had never come along at all. Many high schoolers are given aptitude tests that show the future growth of the industries they showed potential in. These same tests are probably available for free online at this point. Think less about the individual and more about the bigger picture; the individual will get through it and the opportunity to do something grand has much greater return for everyone.

Another way to look at it: a lot of people will work for companies they morally or ethically despise, but the pay and other factors keep them around until they've accumulated enough of this dirty money to go on to use it to do better things. If you are concerned that your best ideas are disruptive to the point of guilt, just remind yourself that you don't need to do it forever, and if you'd feel better as a philanthropist, the bad can fund the good.