True, but you will find that some airlines have already found a solution. Try buying a LX or LH ticket online and you are asked to choose between "I will use coupons completely and in sequence" or "I would like to be able to use coupons in any order". The first gives you a normal fare quote, the second gives you the highest possible fare. But you have made a legally binding choice.
Also, the language in the EC proposal talks only about prohibiting the cancelling of 'return' bookings when the pax no-shows the outbound. It says nothing about being able to check in at an intermediate point after no-showing the first sector.
i.e. if you bought an FRA-AMS-NYC-AMS-FRA ticket the airline would have to board you on the return, even if you no-showed the outbound sectors. However, you still couldn't no-show FRA-AMS and try and board in AMS for the flight to NYC.
I believe airlines experience very few passengers who no show the outbound and attempt to fly the return only. Their issues are with passengers who no-show the return (which they can do little about, unless repeated), or who try and avoid any higher intermediate fare, like in the example above.