Not totally sure I get you, native apps tend to use a combination of placeholders and spinners too (when loading network content). Are you saying people are harsher in their judgement of web-apps, or more accepting?
Vastly more accepting of web apps. Web apps stall, spin (or worse yet don't spin yet are unresponsive), paint in embarrassing frames and masks with old content showing through the holes, and on and on. A native app that did that would be criticized roundly; web apps get a pass for some reason.