I believe that this type of stamps adds nothing to the collector.
Some consider personal stamps ciderellas. To some they are labels. Whatever they are I like the thought that they represent what people where thinking was importent at that time, kind of a snapshot of thinking.
Showing distant events is not showing the wonders of your own country I understand, but done well the stamps / labels and covers are good for topical collectors.
Some do make the distinction of collecting only those personal stamps that will show places and events that are real and of that time in that country. Selective collecting.
Some collect them all.
I like the quality of these shown above and think that whatever the subject matter chosen, they are well done.