Falcon 9 was going to make space so cheap
Falcon 9 was only ever going to make space as cheap as its next-cheapest competitor. It's been ten years since the first booster landings, and no other reusable rocket has achieved a cadence anywhere close that of Falcon 9.
Has Falcon been a loss leader for spacex?
I highly doubt it. With minimal downward pressure on launch price from the rest of the market, they should have been able to make significant profit with every launch. I suspect this has been pivotal in bankrolling Starship development.
If it was such a cheap system due to reusability why are they scrapping it?
Because Starship has the potential to be even cheaper. Falcon 9 still throws away an upper stage with every launch.
With such a “work horse” as SS why wouldn’t they make it accomodate the widest maker possible?
I think Starlink revenue has now surpassed (or is projected to surpass) all other revenue streams, so Starlink has become. SpaceX have essentially become their own "widest market".