Holy crap this is the most dystopian-sounding statement I've seen in a long time. (From the point of view of someone who's never heard of "Soylent" outside of the Charlton Heston movie)
I intend this humourously, by the way. If you're the type of person who hates bothering with food, seems fair to also skip brewing coffee and just get striaight to the source.
Primarily because caffeine is extremely bitter and adding too much will ruin it. I tried to put like 500mg of caffeine powder in my cereal once and it was utterly disgusting. I got about 4 spoonfuls in before I couldn't take it anymore.