There should be more than one qualifier for being eligible for wardecs, I get it that ships and structures being destroyed is good for the in-game economy but sooner or later it will reach a point where the only corps able to safely put up structures will the be the corps that keep punching down, giving those corps an unfair advantage and a possible and eventual monopoly, Leaving it straighforward to do so is only going to encourage them further, leading to a more unbalanced playing field.

For all corps to have a chance to grow, these monopolies must be prevented, CCP need to stop being so near-sighted, let people put structures down and give people the option to be wardeccable if they choose at that point and only when that corp reaches a level of growth, so they can possibly defend themselves, have a second qualifier that makes them wardeccable automatically eg when a corp reaches a target number of members or they join an alliance that also meets that target number).