Imagine that you get your wish-- the strip of land meandering through backyards in Rego Park and southward is turned into a biking/hiking/art show/Oktoberfest/science lab/beekeeping space. Your dream has come true, you use it every day, you love it, it's precious to you.
Now imagine this: some group from god-knows-where comes to your Queensway and wants to turn it into something else, something they value more. Would you be happy about that?
You proponents act like this is a disused vacant lot, an eyesore that is going to waste unless you utilize it. It is not. It's a strip of land that, over 50+ years, has gone back to being forest-- a little slice of wilderness in the city. As such, it is useful and good. Have you heard about forests? They have them in the country, usually. They are rare in a city. Every forest is not waiting to be turned into a park.