Just as there are several types of "power", such as referent, expert, legitimate/reward/coercive, we should understand different aspects of leadership that may, depending on the mix, appear in various types of leaders. Several of the classic attributes associated with "leadership" are, in fact, what we'd like to see in most members of an organization. There are places in most organizations for those who don't have these attributes, but some of the most effective employees and team members - whether or not recognized as leaders possess many of the common so-called leadership traits such as: imagination, communication skills, creative problem solving, tact, thinking ahead and visualizing outcomes, empathy, taking ownership of issues and their solution, respect for others and for differing opinions, etc. These are, in fact, some of the key attributes to look for when hiring folks for most types of roles.
Many of the attributes are essentially important characteristics that we'd like to see across our organizations in most employees and colleagues. In most organizations, folks with all of these attributes may or may not have a formal leadership role, and those with formal authority don't necessarily have these desired characteristics. This is where politics and political savvy enter -- not necessarily as determinants of leadership, but instead as levers by which various people may rise to power.
We've probably all seen situations where the wrong person is in charge, and the "right" person or people don't have the opportunity to lead purely because of politics and formal authority structures. In these cases, it may be a real risk for any in the trenches to attempt to come forward and reveal their capabilities and perspective, as those with formal authority may not be so altruistic and open-minded, but instead see this as a challenge and threat to be eliminated.
Part of the reason it may be such a challenge to define "leadership" is the cognitive dissonance created when we *know* certain characteristics *should* be present in leaders, but aren't there. There have been a number of studies suggesting that many (not all) who rise to power may do so as a side effect of possessing personality traits that lean toward sociopathic behavior (even if only a little): self-interest above all else, the need to obtain and expand power over others, lack of empathy for others, ability to pretend to have all the "nice" qualities when such a role play furthers their own interests, etc. This certainly complicates the discussion, as the wonderful characteristics we're describing may be the ideal, but in fact are not typically present in many executives with formal authority.
These dysfunctional leaders - more appropriately termed "bosses " - aren't necessarily "evil" or conniving, and they may actually believe they're trying to do what's best for an organization. People with personality disorders rarely recognize their own problems. Being confident, assertive and being able to shift blame to hapless underlings may let them masquerade as strong leaders for a time. They often look great to their bosses, only being recognized for what they really are by those who directly suffer the results of terrible management actions. Sometimes the charade can continue for years, harming numerous employees and the organization.
Issues like this are less likely when company culture and process shed light on power silos and closed door meetings, and when rationale behind decisions is open for discussion. Organizations must really understand those to whom they grant power, and make sure they truly embody the right culture, personality and values, lest they empower a management pathogen to run amuck.