When FECI and FECR were all one FEC with All Aboard Florida, the business model made sense. I think that the unwritten intention was to let Brightline be a loss leader of sorts. Even though I think they are planning on profitability, I think the intent was to boost their real estate portfolio and their commercial value. It's that model which led to most Japanese non-nationalized railroad systems. Then, after JNR privatized and became a bunch of JR groups, they too became much more about the full experience - from riding to hotels, to shopping, etc. JR even produces the electricity they run their trains on.
It's good that Brightline fell under FECI and not FECR. If it came under FECR, it would have been obligated to be self-sustaining which would have been extremely difficult. It really takes the whole package. At least with the current model, a financial success to the railroad portion isn't as important as its role in producing commercial profit.