Given the slow advance of the Flexible Use of Airspace concept in Europe, whereby Danger Areas are being curtailed to only being active when they are actually hosting 'dangerous' activities, it might come to pass that D129 H24 status is removed in time. This will of course involve the Danger Area authority having to do some donkey work and issue NOTAMs, but it works for 99% of the other Danger Areas in the country, some of which arguably see a lot more actual dangerous activity.
If that did happen then I think it would be kind of hard to justify the area being notified as active purely because civil gliding and/or parachuting is taking place when the rest of the country has no such protection.
Regardless of the Danger Area activity however, airmanship dictates you should give notified gliding and paradrop sites a wide berth
so there should always be a common sense balance applied between the needs of all airspace users and the availability of unrestricted airspace.