Most national finals do this and it is extremely annoying. The song countries send to Eurovision are meant to represent them and getting an international jury is not the way to select the correct song.
Additionally, the international juries are often scared to pick a song as they don't want to be blamed when the country does bad. The irony here being they almost always choose the wrong song.
It isn't representative of the Eurovision system as most only have 5-8 countries.
My main problem, however, is the countries they do select!
Every one of these international juries has the Uk. Why??? I as a British person can tell you, we have horrible taste for Eurovision! The same goes for other countries that aren't exactly the best with Eurovision.
Instead choose countries like Moldova, Spain, Lithuania or Sweden who seem to actually give the good songs lot's of points!
I also believe there should be a system of choosing 10 countries to be in the international jury!
It goes as follows:
1) the pot 1 (from semi allocation) country that gave you the most points from last year.
2) the pot 2 country that gives you the most points.
3) the pot 3 country that gives you the most points.
4) the pot 4 country that gives you the most points.
5) the pot 5 country that gives you the most points.
6) the big five country that gave you the most points.
7) the country that gives you the most points.
8) culturally similar country.
9) neighboring country.
10) country that is doing the best at Eurovision at the moment.
So for Germany it would look like this:
1) Austria
2) Finland
3) No points, no country. Replace with Iceland as they gave points.
4) No points, no country.
5) No points no country.
6) No points, no country.
7) Switzerland (3rd most points)
8) Netherlands
9) Czechia
10) Sweden