Desire is poison. And it is so simply because we treat it that way.
Ambition is just another word meaning to desire something that isn't is. To resist the present. Only suffering can come from that.
When I first started my career, I had lots of desires. All egotistical. I thought they gave me the drive to strive further and reach higher, until I realise that ambition was simply holding me back.
It was only after I cast off my ambitions that I was free to achieve everything I ever conceived and more.
Some people try to use others' ambitions as a means of control. The carrot - a much more dangerous and sinister weapon than the stick.
What if carrots have no effect? What if you have neither desire nor ambition? Try it. You shed a lot of bullshit and you can finally do stuff you want to do.
I have seen many good people fall to desire, to ambition. Purely egotistical, it impeded their being so badly that they become husks, shadows. Goals are lost simply because desire must be fed with even more desire.
Ultimately, desire and ambition are neither bad nor good. They are simply elements and we who wield it are responsible. We are always responsible, for we lead these things, use them and then eventually blame them for everything.
I believe that we are all responsible for any state we are in because we chose to be in that state.
A lot of people fail to face themselves or their deeds, and their own responsibilities, because it is much easier to complain and to blame.
Accept this yoke, and be free.