there goes nothing above the feeling of dropping a coin / token through the therefore mented coinslot 
Well I can think of a couple of things that do go above that feeling...but you have a point.
However, there could be a lot of problems for a public place (like this) that have these kinds of machines in operation with the coin-doors still intact.
Remember that these machines are still what they were: moneymakers to the eye of the government. You will still need permits normally for them.
I know people who have exhibited their machines in other places (and countries) who got into problems, or at least very lengthy discussions with tax-people, that there was NO need to insert a coin and the machine was on free-play.
I can see why they want to do it this way.
It also adds the (always popular these times) possibility to monitor the machines for statistics.