You'd think the same about 2,952 song and artist titles, difficulty rankings, high scores, and every other reason there's a limit. Even if it wouldn't affect the limit at all, it would be a lot of work for something that doesn't matter at all in the long run. When was the last time you wanted to play the song you bought on February 19, 2010? Or the 764th to last song?
To answer your unfairly worded question accurately, I have wanted a comprehensive "sort by date acquired" option many, many, many, many times. I buy things in bursts rather than slowly, and sometimes I want to find recent songs that aren't brand new, if you know what I mean.