That is a legacy setting that is only used in .NET 3.5 builds of mojoPortal. It was an old strategy for reducing viewstate by turning it off at the page level by default then it was up to any feature that needed viewstate to turn it back on. Vast majority of features do need some viewstate but we have better ways to reduce un-needed viewstate in .NET 4.

The settingvalue was changed to false a long time  ago but I guess we forget to update the comment.

In any case I am removing this setting from web.config so it won't be there in the next release.

I don't think viewstate is used or needed for inline editing, the viewstate probably comes from something else, any .NET control may use viewstate so anything in the skin can contribute some, search input for example, any validator controls updatepanels etc. Some will be generated by the title control for html content because it has buttons for workflow, anything that does postback needs some viewstate.