Somebody must consider the work output of investment bankers to have some value, otherwise that money would never change hands.
You may personally consider their work to have no value for you, or think it is morally dubious, or whatever, but for anyone to be paid, his work must have value to somebody.
The reason I commented is that an artist living off royalties is (usually) reaping results of actual work done, while putting cash into a fund + sitting and waiting, or being a trust-fund kid equals zero effort, so it's not fair to put these in the same basket. I agree investment/trading can amount to real value at the end of the chain, but these are worlds apart.
You may personally consider their work to have no value for you, or think it is morally dubious, or whatever, but for anyone to be paid, his work must have value to somebody.