Why is the Nxt forging return so low?
Nxt is a proof-of stake coin. That means it doesn't need to pay miners to do the work involved in "proof of work". There's no high block-reward, only transaction fees. The fees are set low to encourage people to use the currency. Actually, most people think the fees are currently too high, and they will be lowered considerably soonish. Lower fees will make micro-transactions more viable. Low fees is a basic long-term advantage Nxt has over Bitcoin. (The short term advantage is no inflation; Bitcoin inflation is currently around 10%/year, to pay miners. As the block-reward halves and inflation drops, Bitcoin fees will increase.)
So... What incentive is there for average people like me to forge?
To secure the network. The more honest people forging, the more resilient the network is to dishonest people. If you feel your 10,000 NXT isn't worth securing, you don't need to forge. A whale with 1,000,000 NXT will have more to lose, so probably will want to forge.
Basically, Nxt is not a currency for greedy fat cats to make money by doing virtually nothing.