Because it technically IS just a slightly stronger flu, with the ability to be transmitted farther without people knowing because of the incubation period.
The reason it's a big deal is because it doesn't have a vaccine and the fragile parts of the community are severely at risk. The vast majority of the population will be just fine, but while THEY might be fine, the transmission method allows those people who will be just fine to transmit it to people who won't be fine, or would be much more severely affected.
Every health expert and site says the same thing.
Let's not overblow the effects of the virus. In roughly the same time frame, the flu has affected and killed FAR more people than COVID-19.
https://www.cdc.gov/flu/about/burden...-estimates.htm
That's not to say people shouldn't still be cautious, but this isn't some super bug that's going to destroy the world. Take the same precautions with this as you would the flu (obviously minus the vaccine...since there isn't one) and we'll be fine.