I don't disagree that nostalgia sells, but I do disagree that what we are seeing here is purely nostalgia-driven. I, for one, prefer unrealistic "drift-style" racers to simulations - I get a lot of enjoyment from going as fast as possible, negotiating courses through a mixture of careful positioning and controlled drifts, with the height of skill being completing a lap without releasing the accelerator, without crashing.
Games which deliberately ape the looks & sounds produced by old systems may indeed rely heavily on nostalgia, but there are plenty of other games out there maintaining the old-fashioned arcade driving mechanics, whilst taking full advantage of modern hardware. Personally I would put Mario Kart 8 in this category (although it is debatable whether the Wii U can be called "modern" in the graphics department). In TFA itself, the Power Drive 2000 trailer may have retro music and a retro *feel* to the graphics, but the graphical fidelity itself is not artificially restricted. Elsewhere on Kickstarter, Formula Fusion  seeks to recreate the style and mechanics of the WipEout series, whilst not in any way pretending to be an old game - I for one am excited by the prospect of finally having what is essentially WipEout (in all but name) running on modern PC hardware, with all the bells, whistles and convenience that implies, but would probably be put off if they were to deliberately attempt an original-PlayStation aesthetic. The 90s Arcade Racer  is definitely playing heavily on nostalgia, littered with references to (as you may have guessed) various 90s arcade games, but again, it seeks to make the best of the underlying hardware.
Nostalgia is certainly one aspect of all this, but don't underestimate the number of people who simply find these kind of games fun, and want to be able to play them easily & legally on contemporary hardware! I suspect I am not alone in finding that simulation-style games are not enjoyable without matching realistic controls, but have neither the space to dedicate to wheels, joysticks, throttles, pedals etc. - nor do I particularly want to spend the money or devote the time. For example, much as I am pleased that Elite: Dangerous and Star Citizen exist, I personally am holding out for No Man's Sky, simply because releasing on PS4 first means it is far more likely to have a simple control scheme which works on common controllers. Many will probably decry it as "dumbed down" or "retro"; I say it is just a different design decision.