Saveloys,
It is clear from your comments that you are suffering from some sort of maturity/airmanship deficit.
I speak as a glider pilot and a commercial pilot in training, I feel compelled to say that the lack of understanding you have exhibited is precisely why any half decent glider pilot will have attained a far superior level of piloting and lookout skill than you are ever likely to.
When we are all supposed to be very good at what we do, it is a great shame (and concern) that conscientious and safe pilots should have to work that much harder to compensate for the lack of skill and bad attitude on the part of people like you.
The right of *any* pilot to fly where he/she likes should be directly proportional to their level of skill, understanding, and airmanship REGARDLESS of what type they fly. Sadly for you going on that basis you probably ought to remain in the circuit until you understand a wider range of the topics that affect flight safety as a whole.
As many very well clued up people have mentioned here, you need to understand the bigger picture and assess where you are likely to encounter gliders and when. Then, actually seeing then is the easy bit because they really are not hard to see if you know were to look.
By the way, do you also go around swearing at cyclists when you drive your car?
Happy lookout!
Nish.