1 - this is totally true. The problem here is it's excessively hard to tell someone what their risk profile is. Vulns kinda run a wild gamut, some occuring because you use a vulnerable method, but others because the library doesn't handle crypto right, uses an easy to guess default password, etc...
Tooling around this has been hard to nail down, for a lot of those reasons. Some vendors are making tooling that will only report if you are using the "vulnerable method", but that has to be taken with a bit of caution as well, on account of it can't be 100% accurate.
2 - yeah, sort of. I think the tools do a really bad job as of today of going "well am I actually using this when it's deployed?". A lot of the vulnerabilities in a JS project are buried in devDependencies (which can be totally bad, imagine a bad actor of a library that has a bitcoin miner and now it's in your CI/CD process). Tooling that kinda tailors towards your "deployed" risk profile I think personally is more helpful, because it's about reducing the noise down to what matters. This can be hard to do in certain ecosystems, because for example in Python it's difficult to discern what a library is used for, but in JS, etc... it's a bit easier.
3 - agree 100% here, which is why overall project hygiene is probably the best indicator to if you would want to do that or not. Hygiene is something we should be using at the front end of selection of libraries in order to know that as time moves, we can trust updating, because the library is being managed in a responsible manner.
4 - ambulance chasing, more or less. If everything is an emergency than nothing is an emergency, either. Agree with you there, and I think the tone that has been set by companies in this space is not exactly right, but it originates from you know, trying to sell their stuff. Those posts likely resonate with AppSec people more than Developers, hence why they keep making them. That's just a guess however.
Full disclosure, I work at Sonatype, and I work on a lot of the free tooling related to security scanning. Don't like how it is all playing out? Come work with us. Our tooling is open source, and we truly want to help developers out.
Couple projects I think people would benefit from, and are community driven/participated in:
Golang scanning: https://github.com/sonatype-nexus-community/nancy
JavaScript scanning: https://github.com/sonatype-nexus-community/auditjs
RubyGems scanning: https://github.com/sonatype-nexus-community/chelsea
Conda (and soon PyPI) scanning: https://github.com/sonatype-nexus-community/jake
R (CRAN) scanning: https://github.com/sonatype-nexus-community/oysteR
We try and write these native to each ecosystem so that developers can work with us on them. Also we have them setup so you can use them anonymously by default, we have to eat sandwiches (or whatever your chosen food is) as well, but we try and provide tooling that all can benefit from. Come help us if you want!