100% agree with the statement that overall voter participation needs to increase from current holders and even new investors need to be encouraged to vote.
Though, building a new incentive system around voting is an idea that has been floated on Polkadot and even tried outside of it. The main problems that arise from that are long term investor disenfranchisement and most importantly automatic voting which is nearly impossible to get rid of. The easiest way to vote in a system that requires your vote participation is to either instaNAY or instaABSTAIN everything. A third potential issue not to be overlooked either is spam referenda.