Why does iMovie 09 use so much RAM when creating thumbnails?

[aiqw9182]

Seriously, it's absolutely ridiculous and brings my entire system to a crawl until I restart. Just look at how many page outs I have after iMovie is done making thumbnails of one seven minute clip:

My CPU usage during this process was around 10% so what gives? I have an early 2009 iMac with 4GB's of RAM.

 

[C-lon]

Because Apple likes to use a lot of unnecessary things in their programs/applications. Lol I honestly don't know, but this is what it seems like for me at least.