property with negative cash flow

[Kundan Chand]

I am first time looking to buy a residential condo in Orenco station area Hillsboro for $290K, which rents for $1700. But when i put in the numbers, the online calculator shows negative cash flow. I was thinking that if someone else pays down my mortgage, it should always be no brainer but seems like people in this forum always insist on positive cash flow. I have a great paying full time job which i hope to continue another 20 years. Then why is it a bad idea to buy property with negative cash flow. 

http://www.calculator.net/rental-property-calculator.html?cprice=290000&cuseloan=yes&cdownpayment=35&cinterest=4.75&cloanterm=30&cothercost=3000&cneedrepair=no&crepaircost=10000&cafterrepairvalue=150000&ctax=3700&ctaxincrease=3&cinsurance=800&cinsuranceincrease=3&choa=4800&choaincrease=3&cmaintenance=2000&cmaintenanceincrease=3&cother=200&cotherincrease=3&crent=1600&crentincrease=3&cotherincome=0&cotherincomeincrease=3&cvacancy=5&cmanagement=0&cknowsellprice=no&cappreciation=3&csellprice=200000&cholding=20&csellcost=6&printit=0&ctype=&x=121&y=22