Some people just don't have the work ethic to make albums.
As you guys know, I'm a recording artist. Over the past 5 years or so I've been writing rhymes and making albums. It takes me about a month to write 50 verses. In the time it takes to write 50 verses I pick beats, some of the beats I make myself, other beats I find on Facebook groups or Youtube from unknown producers, and sometimes I use classic instrumentals that everybody will recognize. In the time it takes to write 50 verses, I pick out beats and then I figure out which rhymes will go with which beats.
It takes about 6 weeks to make an album with 22 songs (22 represents Victory because V is the 22nd letter). I currently have 25 albums with 22 tracks each. I have hundreds of songs.
My point is that some people just don't have the work ethic to write rhymes every day and record music. Sometimes you hear an artist say, "I'm working on an EP" which is ridiculous to me. I can write an EP in 2 days and record it and mix it down in a day.
However, when I was younger I couldn't write rhymes. From the time I was a teenager until my late 30s I probably wrote 1 or 2 rhymes. Some people just can't do it. Some people just can't get a pen and pad and write 50 rhymes. I know what it's like, I had writer's block when I was younger. I know what it's like to not be able to write rhymes.
2Pac was in a space where he could just grab a pen and write a song in 15 minutes. Some people just can't do it.
A lot of the older artists that Nas is speaking of probably just can't write rhymes. I recall hearing a rumor that Rakim has writers block and can't write rhymes. That's why you always see him performing his classics but he never releases new material. KRS One is the opposite, he drops an album every year.