Where is it the sole resposibility of a drone pilot to avoid a aircraft?
Did you read what I wrote? It is every pilot's responsibility to avoid a collision. That doesn't matter whether the pilot is in the air or on the ground. Do you imagine that the pilot of the chopper that was hit flew into the drone deliberately, just because he had right of way? Don't be silly - he collided with it because he *did not see it* until too late to avoid it, if at all.
What the hell are you doing below 400ft if not landing or taking off?
You may not have heard of ridge soaring. It's gliding using the rising air caused by wind blowing towards a ridge - you'll often see it at coastal flying sites, or at inland sites where there's a long ridge facing the prevailing wind - good examples in the UK are places like Dunstable Downs or Long Mynd. Unless the pilot finds a thermal, he's not going to gain much height and his altitude will be largely controlled by wind speed.
Stay out of the air then, what you think that you own the airspace?
In some cases, yes: paraglider sites are often either owned by the clubs or used by careful agreement and negotiation with the land owner - and the landowner's rules often state that only specific people and/or aircraft may fly there.
At many flying sites, airspace is shared with model aircraft fliers. Because of the difficulty of judging height and distance from a ground viewpoint, such sites have well defined areas as to who flies where. As long as pilots respect those areas, there is no contention.
Cooperation is the way forward, drones are here to stay, so you better get used to flying aroud them...
For cooperation, see above. And I suspect you're right; drones are probably here to stay (unless they're legislated out of the sky, which is unlikely in the short term). But please remember this: as a drone pilot, you're used to an aircraft that can go from high-speed flight to hover in seconds; that can make course and direction changes effectively instantly. A paraglider moves forwards at 20-40kph in normal flight and cannot stop; it can't change direction anywhere nearly as quickly as the drone can. (The German DHV basic qualification test requires that a pilot perform a 360 degree turn in both directions (i.e. one left, one right) in under thirty seconds, which might give an idea of speed of turning).
For all practical purposes, paragliders *can't* fly around a drone; larger and faster gliders and powered aircraft are unlikely to be able to for the same reasons. I haven't seen a drone flying with high visibility lights on - is this something considered in the drone world? Strobes, for example? They'd at least improve the chances in VFR flight which is where most general aviation happens.
Please understand: I'm not trying to ban drones, and I'm not trying to ban you: I'm asking that you give consideration to other fliers - the same 'get used to it' that you're asking for.