Even a half hearted RTS would be better recived, how can they not know that?
Couldn't be more wrong. The market for new RTSs is too tiny and saturated to turn a profit on any new IP. The small existing player base is too entrenched to move away from the old established IPs that are still popular to something new and unproven.
Given that Marathon is unlikely to ever make a profit, Tempest Rising technically made infinitely more in profits than Marathon did.