> Because Elon lied to humanity about their mission, in order to secure his position.
Setting aside feelings about Elon and whether he misled anyone about the mission of SpaceX, saying "Our mission is to put humans on Mars" didn't help secure any position, except some popularity with the Mars Society, sci-fi fans and nerds. It certainly didn't help SpaceX get financial support from big money hedge funds, governments, Wall Street analysts or NASA administrators.
If anything, setting a goal of what was then only a nerd fever dream, and which even today has no clear path to profitability, hurt SpaceX's early position substantially. The only thing that eventually turned around that "screwball billionaire blowing his money on a vanity project" perception was developing a launch system able to deliver orbital payloads at a dramatically lower cost per pound than anyone else.
As to whether Elon misled anyone about SpaceX's long-term Mars goal, anyone who listened to his in-depth interviews from early on heard him repeatedly say that getting there would first require making SpaceX a highly profitable commercial enterprise because Elon didn't have enough money himself, NASA payloads alone wouldn't be enough and government can't tax a meaningful portion of GDP only to spend it on a goal most people don't value much. Even if Elon hadn't said it, it was already obvious to anyone who understands how government, finance and funding multi-billion dollar projects work. There's no other realistic way it could happen. Starlink and payload delivery are on track to make SpaceX profitable, so how was anyone misled about SpaceX's objectives?
Personally, Elon's Mars talk turned me off too. While a permanent Mars colony is inspirational for sci-fi fans and Singularity types, there are much more productive things to focus on first if the goal is to accelerate humans becoming a space-faring species. The hardest part is lifting large amounts of mass out of this planet's gravity well economically. To then immediately go drop that astronomically expensive mass down another planet's gravity well seems kind of... unproductive?