The classic content appeals on so many levels. For a start these cars didn't have traction control or abs so they make a natural fit for gamers who like to race without driving aids.
The classics vary greatly in drivability, but particularly the older ones are not normally absurdly powerful so they are accessible to almost all skill levels. The Sports Cars used to be driven to the track and Le Mans cars were road registered so even though in race tune, they have a reasonable level of tractability.
This game enables us to relive or recreate famous races from the past and imagine being the co-driver, using in many cases the original tracks.
If you visit some classic events you will probably find that the race and meeting provides so much more interest than a modern event. The modern event will provide racing and if it is a junior formula, the opportunity to spot and follow rising stars, but probably not much else as the cars are often virtually identical.
When you visit a classic meeting, as well as the racing itself you normally have a much greater variety of machinery so more technical interest - and often you can see different solutions to similar technical problems. You have the interest of the drivers in the machinery which often borders on devotion - especially if the car was previously raced by famous drivers. Each car has a history and especially if you can visit before race day, the drivers and mechanics will be happy to chat about the car and its history - they are often too busy on the actual race day. That history sometimes spans many drivers, countries and different race series.
With classics, that visit to the track can spark a desire to find out more - you have youtube footage, race entry forms and programmes on the internet, books by mechanics, drivers, team managers and owners. Rare motor racing books are easily accessible online. Further visits to the track and chats with drivers and mechanics. It can be an obsession - a magnificent obsession!
Then you can take a break and drive those same cars - thank you SMS for the TR 250 and GT 250 - more please!