So my question is What do you think ?
I'm not certain whether all of the simple/buggy/harebrained electronics projects are actually intended as scams by the project founders. For various reasons then many, many people are anxious to try and find alternative careers these days, and many will do so by trying to turn a hobby into a revenue stream. Add a lack of formal education (or just some relevant on-the-job training under the supervision of a Greybeard), plus people's general inability to assess the limits of their skills, and you have the current mess.
What I am also curious about in many cases, is what the supporters believe they are getting? Even for the halfway well designed projects, you are still looking at adding some minimal amount of front end filtering, plus some rather hair raising software. My suspicion is that most people wouldn't enjoy having to write the DSP code for making just a simple FM receiver, not to mention a 'proper' cell phone implementation, or a GPS receiver.
The choice of frequency ranges of some of the SDR projects also seem rather odd, as seen with a hobbyist/self education perspective. The projects are probably limited by what RF ICs are available, as the project founders may be unable to design the needed custom RF circuitry themselves.