Still on my mind

I can't forget this Garbage Patch thing.

This is from the San Fransisco Chronicle.

• Contains PVC which is degrading - turning into dust because of the UV rays.
  
• All sorts of other things - from plastics to tires
  

Why can't plastic be recycled?
Apparently there are some problems.

1. The used plastic from bottles cannot be used to make new plastic bottles. This, I think, is because the recycled plastic will have to be mixed with plasticizers which will then make them unsuitable for storing food. Can used plastic be lined with poly-ethylene like metal cans are lined? This will surely separate the reused plastic (with the plasticizers) from the virgin plastic and the food will be safe.
2. The chasing arrow symbol with the number in it does not necessarily mean that the plastic can be recycled. - This I did not know.
   
3. I wonder what kind of plastics can be recycled? Seems like PP, LDPE, HDPE, PET, PVC, PS can all be recycled. Only the ones with "7" in the chasing arrow cannot be recycled.
   
4. Also it seems that less than 1/4 of the plastic is recycled in most cases.
   

Need some strategy.