I found this analysis of Idealism, from a link to a site about control on another thread. On this site, idealism is seen as a negative to be overcome. The site defines idealism as -

- Holding on to a set of beliefs which are a rigid system of the way life is "supposed to be" or "should be".

- Philosophical foundation of a lifestyle in which you find yourself always "bucking'' the system at home, school, work, or in the community.
   
- Belief system you have adopted about how things "should be done'' which often gets challenged by the way things are in reality.
   
- Underlying motive behind your attempt to control people so that they meet your ideal image of the way they should be, act, achieve, react, live, etc.

- Block which prevents you from playing the political game of going along with the mandates of the authority which temper your beliefs and "should's" about the ways things should be.

In this site, idealism seems to be an excuse, an obsession, a delusion, a bitter thing, not a positive thing.

So I looked up Wikipedia on Idealism , and found a bunch of links to a lot of esoteric philosophical debates about idealism. Wikipedia also commented :

"More accurately Idealism is based on the root word Ideal meaning a perfect form of and is most accurately described as a belief in perfect forms of virtue, truth, and the absolute.... In general parlance, "idealism" or "idealist" is also used to describe a person having high ideals, sometimes with the connotation that those ideals are unrealisable or at odds with "practical" life."

I found a comment here that describes the trap -
"IDEALISM is a product of the gifted intellect: a vision of what is possible, what could be. It is a positive quality - the driving energy that propels a gifted person forward towards achievement. Problems arise when idealism becomes perfectionism: when what could be becomes what should be - an imperative!"

To me, this says idealism is a first step to achieving something - by having a vision of what can be. Perfectionism is the imperitive that stifles creativity - and limits the outcomes.

But I like to think that idealists can achieve, that they are positive movers and shakers who can make something happen, rather than whingers who stifle debate and control outcomes.

Can an idealist ever achieve anything?