Depending on your municipality, you've probably got other options for recycling of a greater quantity of materials, or materials that are simply too large to place in the appropriate bin. Ideally, these items are routinely collected from your home, or can at least be scheduled for collection, in order to make the practice more convenient.
The public bins are sometimes designed like this:
- To avoid people simply dumping a bunch of rubbish in them, most of which probably doesn't belong in them (but perhaps the others)
- To avoid one or two people filling them up with their haul of stuff, and everyone else piling stuff up around them between scheduled pickups of the materials.
Mine are actual converted square rubbish bins. While the lids aren't large, the opening is sufficient to accept something around the size of a sack of fast food. Twice weekly, I see folks from sanitation sorting it all out prior to hauling it off because people consolidate their stuff into a bag, then plop it in.
A smaller opening would be less convenient for depositors, but more optimal for the folks that have to actually handle the stuff. It encourages (and sort of forces) folks to take the time to put a predictable quantity of things in (hopefully) the right places.
Not ideal, but I suppose a compromise most can live with.