But I learned that he was actually a very rich man and spent a lot of time in Manhattan hotels and was financed by JP Morgan.

He was financed by Westinghouse not Morgan. He died a pauper and had a lot of really far out spacey ideas not based in reality, but he did have periods where he was well to do. Not Westinghouse or Morgan rich, but pretty rich.

People also say that Edison was a businessman and even tried to hire tesla.

Other way around. Tesla tried to get a job working for Edison. IIRC he worked with Edison briefly where Edison gave him meaningless work and shorted his pay. But here is the deal about a shop that invents things. The engineers don't get to tell the ideas guy what the company should be doing. Once he get funded by Westinghouse he was able to patent every one of his ideas.

I was wondering if he was such a great scientist,why aren't we taught about him?

Because in the grand scheme of things he was a small player. His inventions involving AC and induction motors were very important as were his contributions to broadcast radio. But you could also make a strong argument that these were a natural progression of the existing math on electronics and that he was just the first to put it all together. The really big players of gilded age electricity were Westinghouse and JP Morgan. To a lesser extent Edison. If you only take the oatmeal version of gilded age history you miss out on a lot of the most interesting stuff.

There were patent wars over the light bulb in much the same way Apple, Motorola, Google, and other tech giants battle each other. The whole Edison screwed Tesla thing has next to no basis in reality. Unless you count not giving someone a job as screwing them over.

If Westinghouse hadn't supported Tesla because he wanted Tesla's patents you probably would have never heard of the guy. My favorite story of the Gilded age is of why General Electric is called GE and not Edison Electric. We all know the story about Edison thinking that DC was the way to go with power distribution. What is downplayed is the fact the JP Morgan fired him from his own company for refusing to see the winds of change and adopt AC technology. In a fantastic moment of sour grapes he said he was in the invention business and not the electricity business.

And all this Oatmeal version of history downplays how big of deal Edison actually was. Edison first got fame and fortune with a lot of telegraph patents. The Menlo park laboratory was run in a way very similar to how you would expect engineers to tackle problems in the modern day.

I highly recommend looking into what actually happened in the gilded age with the roll out of the light bulb. Cause looking at this thread you've just been told a bunch of really inaccurate stuff.