That's where you're mistaken. Xavier manipulated a group of children into saving the world multiple times. There was no team just his own personal army and his decision making was unilateral.
And it's been argued in the X-books that it was so he could be untouchable by the US government.
Also not sure why you put S&M in there or what that has to do with being "evil"
In the issue it's also shown that Xavier uses his powers to get rich again despite the X-Men having control of the estate. And that he also corrupted children. So those points go both ways
If Xavier hadn't acted:
Scott would have been manipulated by a diamond-skinned telepath into a life of petty crime. Facts.
Hank would have been enslaved by the Conquistador. Facts.
Bobby would have been lynched by his townspeople with the help of the police. Facts.
Jean would have stayed in a catatonic stupor. Facts.
Maybe Warren would have been okay on his own, but not the others.
Further, the entire world would have been destroyed by the Z'Nox aliens if he hadn't gone into seclusion and prepared a plan that utilized his expertly trained 'child soldiers'(who were all over 18 by then) in perfect tandem.
Let the flames destroy all but that which is pure and true!
Let the flames destroy all but that which is pure and true!