Lets face it, if someone asked you to start this ferry business, (from PH to CBD) would you? Try and calculate potential costs and potential revenues; license to operate from Malaysia side, license from Sinagapore side. Docking/berthing fees, Vessel insurance, insurance for passengers, flucuating fuel costs, ferry personnel, safety equipment/recurring inspection, respective taxes. losses from non operational times, due to bad weather/mechanical failure, etc, . Liability from season pass holders, requirements from authorities, blah, blah, blah....
I heard from a ex maritime person, that it makes no sense to do it since the distance was greater than to Batam, and you would have to pass-by one of the busiest ports in the world next time (in Tuas) avoiding all the traffic.
I'm not saying its not possible, but it'll take a long time to build the critical mass before it becomes viable. Also no weekender will go from tampines to CBD/Harbourfront to visit PH to eat in a mall, and see Hello Kitty. A three hour return trip on bumpy seas aint gonna be fun for the parents and kids. (Not forgetting the risks by sea are arguably more than by road). So where's the weekend crowd coming from.
PH like you say is more upmarket and exclusive, by the same token you are not going to attract the tourist crowd that goes to Batam for seafood/whores galore, Go- karting, bungy jumping etc..
BTW. Not looking for a fight. Just keeping it real.