Recycling plastic is a good thing. Here in Finland it has been organized pretty well. It has even been enforced in law in certain level.
Producers and importers of products that are packaged into plastic are obligated to arrange the collection of such plastics by the product responsibility law. Obviously it is us, the consumers who are paying for that.
That's a good thing, but there is a catch. As the producers are only obligated to collect the packaging plastics they can only charge us for that. If we put any other plastic in the recycling they need to pay the expenses themselves. So instead of enabling the recycling of all that other plastic it all should go into mixed waste. There isn't even an option to deliver such plastic anywhere to be recycled.
Companies only do what they are forced to do, and are getting paid for. Not all packaging plastic end up in recycling so there would be some leftover budget to handle that other plastic as well. But of course companies see that as a savings and are reluctant to use their hard earned cash on anything extra.