Tell Randstad that you'd like a Python/Django developer and they'll throw 20 people at you that all have one thing in common: They don't know Python, nor Django.
I bin them, but I suspect there are at least a few people who will go "hey, I can wing that" and respond depending on their level of desperation.
Several years ago they sent me on 3 job interviews. The skill sets matched up nicely and the companies were nice, but none of the companies could meet my salary/benefits requirements (which weren't that extreme given my experience and other postings around). Randstad knew my requirements and sent me there anyway. I was able to find one of the company's public posting of the position (afterwards) with their offered salary range and it wasn't close.
They essentially wasted my time, and the company's time sending me on interviews that were highly unlikely to land an accepted job offer.
Add this to all of the contract or contract-to-hire positions they kept trying to push on me despite me being adamant that all I wanted was direct hire/full time.
Sounds like regular job postings huh? We get people who don't know JavaScript (as in, never used it) all the time for JavaScript job posts.
I think specialization of labor applied to the software stack is actually so much more critical now than it ever has been, and that in truth most places that seek to structure themselves around the idea of "full stack" only do it under some misguided belief that it's somehow cheaper or more efficient to employ people who can supposedly "do it all." It's further dysfunction when you see postings asking for very inexperienced recent grads who are also somehow gurus in 5 or 6 full-stack domains.
"Full stack" is generally an outgrowth of bad management ideas, and sends up red flags about companies and teams that believe it's super important, or that very competent engineers with experience wouldn't be able to pick up the skills they need quickly because they have "never gone full stack on web" ...
I see a few of these kinds of things that are somewhat tied together:
"Doing things at scale" -- but doesn't actually define the scope of their specific problem in the job listing or the interview. They seem to believe there is some singular platonic thing that is "at scale" for all problems and all situations.
"Full stack" -- but list conflicting skill sets for a position, or (worse) basically admit that they have no idea what you'll be doing for them. If you're trying to hire a machine learning Ph.D. with 6 years of experience in Javascript, then something up the hiring pipeline at your company is messed up. The drive to do a ML Ph.D. (generally speaking) is not really compatible with the drive to acquire 6 years of Javascript experience.
"Fast-paced" / "constantly-changing" environment -- The job of business developers and managers is to present a stable double-sided interface. One side faces customers and the stream of business problems that Nature creates. The other side faces the employees who then implement solutions to those things. Yes, you can't control the problems that nature throws at you. But you can control the way those problems are ingested, broken down, analyzed, and presented to the workers who will solve them. When a business punts on this and basically says anytime Nature throws us something tricky, management will just jerk you around under the infinite excuse of "fast-paced environment" then you should have serious, serious concerns about whether those business managers are actually going to be successful, or whether they will show respect to the intrinsic human need for adequate work/life balance and professional respect for your position within the company.
But I am fully confident that a team of "full stack" generalists can be effective as well. I don't think the idea is "such a harmful concept to the profession of programming" at all.
When you're hiring for a web position, go ahead and hire the guy that has never used JavaScript in his life, and leave the "full stack" people that have actually built things in that domain for me :)
When hiring for a web position, hire a web developer or a person whose engineering skill leads you to believe they will solve the web development problems. That's my whole point. Web developer != "full stack". Hire someone else for the database side, and have them work together. The two specialists, say, are worth much more than someone you venerate as "full stack" and make do both things.
However, even though I'm not actively on the market, I frequently get contacted for .NET gigs (even though that comprises 1% of my work experience, having spent most of my time in ColdFusion and Ruby). More often than not, they're out of state recruiters, and I suspect the actual recruiter is offshore, and they're throwing stuff at the wall to see what sticks.
One suggestion for you: When you write up a job description, break down the requirements into clearly labeled groups like "must have", "nice to have", etc. Makes it easier to hold them accountable for what candidates they bring you.