This is only true in areas where endemic flora and fauna remain established; definitely not the case for this particular area and other areas I have visited with similar improper harvesting.

The main purpose for these trees being planted since the 1920s was for aiding in reforestation and soil erosion prevention. Aside from these trees (in this specific area), there arent many native plants around. In fact, they are playing a significant role in controlling a far more invasive plant,  leucens Lecocephela (we call it haole koa) which has destroyed entire ecosystems and created monostand forests.

The tree in the photo above continues to play a significant role in preventing soil erosion in its specific location. So regardless of its invasive nature,  the trees being observed do play major roles in their particular area, and over harvesting like this can create voids which will be filled with other problems that have far greater circumstances.

Just as in any forest, management is key to prevent invasiveness and overcrowding for any species, and the management of AC can be done in a way that benefits both the ecosystem and explorers alike. The tree in the photo above is in an area where its not having a negative impact, and in fact plays a key role in that area,  so this type of harvesting cannot be justified as essential management.