It doesn't have to. At its best, PIP is a very open, transparent, communicative, supportive method - here is what we need; here's how we believe you can help us; let's work together to meet our mutual targets.

As others have said, in a good company and team, PIP is one amongst many coaching tools, rarely the first one, and can be useful in various situations - somebody not taking a hint or being oblivious, indicator of seriousness, but also to those with potential who need structure and benefit from explicit list. And yes of course, a paper trail and a documented process if things don't work out for various reasons.