How many people do the lottery? So perhaps highlighting the wins might be better?
As an old friend of mine used to lament, 'in the UK people tend to be incentivised by money, sex, booze or violence'.
Other comments I've heard centre around the fact that as a spectator sport it just isn't a very good spectacle. The action takes place at a distance and intermitantly. Anyone I've ever taken racing for the first time I'm praying that they win something in the first two or three races as you can physically see their morale leaving them otherwise, as they wonder why they've bothered to try and pick out a few dots at the 2 furlong pole and possibly get excisted for 20 odds seconds, every half hour. Without the thrill of winning a racecourse can be a particularly desolate and unpleasent place.
The other thing that occurs to me developing Greys points about other sports, is that all those he lists, are to some extent, accessible to spectators as participation sports too. Football, Cricket and Rugby I was playing as a child. I'd swing a tennis racket in my early teens for 2 weeks in year, and could pick up a few wedges on the local pitch and putt. It might not have been much, but the very fact you were able to experience a bit of the game yourself at least gave you a connection and bonding with it. By contrast racing was not just a long distance viewing sport, it was also inaccessible compared with other more easily accessed alternatives. Even motor sport has been able to get round this to some extent with the advent of computer games.
The other major (though not necessarily terminal) problem it might face is that there's no real team to support, and with a few exceptions you can't build up a following beyond the 4 or 5 year life span of a 'public horse' or a charismatic jockey. I know they've tried to address this through things like the Shergar Cup, or that Haydock race that involved jockeys wearing football shirts, there's even this Ireland versus UK scoreboard that Ch4 so belove of Cheltenham, but it's never going to work.
The bottom line is we live on planet football, and with no obvious end objective to a season, racing is seen as series of disjointed unconnected events. As Grey also says quite correctly, for most people it used to be an unwelcome and irritating interuption of a sport that people would prefer to watch.
I've always felt it was a decent product 'trying to get out'. The more I think about it though, the more I realise just how much is stacked against it, how much its out on a limb, and how much its increasingly falling behind the trends of the day in entertainment. Even something as sedate as cricket has been able to make 20/20 work, and due in no small part to Indian investment, sits on the cusp of a lucrative future. In the last world championship snooker profiled it 'snooker sixes' (number of reds) and seems to have been well received (mind you, they've got a Chinese market to milk).
The core of the problem has to be attendance prices, as the sport is primarily designed to take money off you from the moment you pay to enter. You don't pay to go into a pub do you? With better television pictures providing closer views of the action, and with on line exchanges providing better prices than on course bookies (many of whom are taking the piss with their e/w terms) what incentive do we have to travel with todays petrol prices, to pay £15 for a ticket that limits you to a restricted area?. I got caught out at Thirsk the other night trying to buy a members badge, and not being allowed to for the lack of a shirt collar and tie!!! alright i can understand this at Ascot (don't agree with it) but for Gods sake, a Sunday evening meet at Thirsk, when the first race up was a 5F seller!!! (I have to say, I otherwise liked the course).
The other complaint I frequently hear is the lexicon of racing and the confusion caused by fractions. It could of course be that our maths teachers have failed a generation, but I would have thought we could easily follow the PMU and various Totes, as well as the exchanges and move to decimals overnight.
The racing lexicon if explained properly could actually become part of its slightly eccentric appeal. It certainly doesn't seem to have made cricket too daunting for people, and racing has got nothing on the complexities of the ever changing laws of rugby union.