They might as well be.
Tho nobody really likes these songs, except when drunk while doing karaoke. Then it's ok.

I mean, I can see why people in APH-Fandom would want to interlace little sentences of the character's native language into his speech now and then. To make it more characteristic, to remind people perhaps, that this character is special because he/she is FOREIGN.
But usually it's done so blatantly and into-your-face that you just want to facepalm. I don't mind it, but it has to be done tastefull and with finesse.

Awww I like them! XD But then I like cheesy karaoke music hahaha.

Yeah, doing it tastefully is the key here. You can't have some situation where, oh I don't know, Germany and Italy walking down the street and then Germany just goes "Blahblahblah" in German to Italy. That's awkward. Now if they're walking, Italy distracts Germany, and Germany steps in dog shit and it pisses him off, you could have him cuss in German. That seems more... believable. Now if it's tasteful or not, I can't really say. XD;