6 deviants said it will help teach non-vector artists what vector is!
5 deviants said people who colour in your line art will feel good and remember their childhood experiences in connecting with art for the first time
4 deviants said it will help gain the vector community exposure and awareness
4 deviants said by practising your line art skills you can learn and improve ways to minimise your point count
4 deviants said you might get pimped in a similar poll or news article so more people can see your line art!
3 deviants said all the cool kids are doing it, be part of the cool crowd (if you're into peer pressure!)
3 deviants said it's fun to get involved with community projects on deviantART
3 deviants said And if you don't know how to draw but know how to vector... why not try doing the line art for many of the sketches available to ink from this news article [link]
1 deviant said it will help gain YOU exposure