Not necessarily true if they deem that the cost/time to make the PS3 version work isn't worth the revenue it will bring in.
When I worked in the business sector we called that Investing in the future. Take a small loss or a reduction in revenue now to safeguard Goodwill and future sales. Any business worth it's salt will tell you Goodwill is not a word to be bandied about lightly as it has the potential to add millions to the value of a business, customer confidence can make or break even the biggest companies.