'Orthogonal' is the strong claim I'm disputing; other WP process does not create the same problem. For example, editing someone's contribution to improve its voice/NPOV or suggest verification can encourage casual contributors; it's positive attention. "I got something started, others are paying attention, progress is occurring. Fun!"

Deletionism -- whether the judgment that something should be deleted or following through with deletion -- is negative attention. It uniquely discourages contributors and often destroys content of small-but-positive value. (For example, it destroys the important 'first drafts' of topics that will someday easily pass 'notability'.)

Deletionism also shrinks the territory on which collaboration can occur. A deleted article can be neither corrected nor improved; it is a void. Perhaps there is someone somewhere who could add the citations... justify the importance... benefit from the partial information -- but deletion forecloses that possibility, even though cheap storage and cheap search means incomplete scraps of information can better find their audience/editors than ever before.