BEST PICS BEST INFO They say it contains 250'000 cubic metres of water, but what they don't say is how much of that is pee.
I'm no businessman, but I'm sure there are far better business plans than spending a billion pounds to build a massive salt water pool next to the ocean.
According to the article, the pool's significantly warmer than the ocean, so there's one difference. It also appears to have no waves, the water's much clearer, it's presumably restricted to the hotel people and you have direct access to hotel facilities (places to buy food/drinks, those boats, etc). These things are not necessarily desirable for everyone, of course (I love waves!) but if enough people want to have them as well as the regular ocean (or even instead), then you have a market for it.
There's also the safety factor: they can let little kids play in the ocean, without them really playing in the ocean.
Indeed - no currents, no unforeseen depth changes, etc. There's probably also a specific section for kids, shallower and with flotation devices around. That sort of thing could be quite appealing to people with little kids who would worry too much about them if they took them to the sea.
There's also the significant lack of evil undersea life. Last time I took a dip in the ocean a ray got me. You wanna know what's not a good time? Being six months pregnant, limping a half a mile up the beach to get back to the hotel while blood runs down your ankle and your three year old wants to know why Mommy's crying. tl;dr, I'm all for the faux-ocean-next-to-the-real-ocean.