First: Compare the time you need to check an institution vs. the time you need for assessing a job candidate (in particular the former only has to be done one time, the latter for each candidate).
Second: Nearly all universities in Germany (in terms of quality of education) can be considered as rather equal. On the other hand: If you have a graduation certificate from a university in a country, where this is not the case, you will, indeed, be doubted, if it's not from a internally renowned university. Similar things hold for the German academic scholarship programs (there are only seven or so big ones in Germany and you know which focus they have on the candidates).
> Yes, as long as the institution is reputable this is a pretty good heuristic.
Third: This is why you preferably get certificates from reputable institutions (for Coursera, the fact that Stanford offered courses there gave some initial credibility; the same holds for edX - MIT).
Fourth: The fact that I got certificates on Coursera from not-so-renowned universities, too, doesn't make them worthless. They'd only be doubted to show deep knowledge in the topic of the course. They still show that I'm willing to upgrade my education on my one (something that employers, of course, love to see).
