The columnist’s reason for the argument’s inadequacy is neither sufficient nor necessary for the argument to be inadequate, so we’re not dealing with a flaw of sufficiency vs. necessity.

The columnist rejects the wildlife activists’ proposal solely because it won’t completely stop animals from being electrocuted by power lines. But the proposal would still lead to fewer animal electrocutions, which could be reason enough to adopt it!

The columnist did not say that the proposal shouldn’t be adopted, just that it shouldn’t be adopted based on the wildlife activists’ argument. There was therefore no need to consider any possible additional advantageous effects.

The columnist does not criticize the wildlife activists.

The columnist does not mention any other proposals for addressing animal electrocutions by power lines.