What is the purpose of an 8 point garbage matte? - soft edges

[HeyAndy]

Why do some filmmakers integrate soft edges in a shot? Is there a purpose to them? Or are they just for aesthetics?

These videos are just examples on what I mean,

http://www.youtube.com/watch?v=W5zEWE2H6g4&playnext_from=TL&videos=U2Lj6FirpGs

http://www.youtube.com/watch?v=-CCCrkm5SRM&playnext_from=TL&videos=U2Lj6FirpGs

http://www.youtube.com/watch?v=Xy8jdBSwAto

Thanks

[Huy Vu]

Adding a very slight soft edge or vignette can be useful in drawing attention to a particular area of the screen. It should be used sparingly and subtly IMO.

[David G. Smith]

Yeah, I think that the above examples are used to for aesthetic effect and the out of focus foreground helps add depth.