I'll try and say this as respectfully as I can that it is generally ignorant advice to argue that it is beneficial to not have your license. That is to say someone who is going full time into real estate. Depending on your brokerage it can drastically expand the opportunities that become available to you. Worst advice I received was to not get my license and the next worst advice I got was to join a small brokerage
Some other important benefits are you can legally and effectively sell people's houses if you don't want to take advantage of the deal; without investing your own money and making a percentage of the sale! If I have a seller who I cannot come to terms with on price I have the option of Listing their house (or passing it on to another investor and facilitating the deal).
I represent other investors on deals that I may not want to buy (which is the majority), I've established relationships with private money as a result.
And lastly, when people say there are no deals on the MLS, that has to be the most misguided advice of all. 93% oh all deals are done using a realtor meaning that 90+% are done on the MLS. That being said the BEST deals may not (or may) be on the MLS. I've gotten amazing deals on the MLS. But a lot of times you have more control when the deal isn't available to the public. Just put it like this you can get out negotiated OR get a great deal and walk away a champion whether it's on the MLS or not !