People who actually understand statistics are rare. I can probably weed out 1/3 to 1/2 of candidates simply by asking what a p-value is, or what precision/recall are (this includes people who said they worked in search).
Of the ones who know basic stats, most are neither good at nor interested in programming. They just want to use existing libraries to crunch numbers in a Jupyter notebook, then hand that off to the developers.
Finding a person who can come up with a predictive model, understand what they did, optimize it without breaking it's statistical validity and deploy it to production is very hard.
(If you can do this, I'm hiring in Pune and Delhi. Email in my profile.)
(not sure I can defend somebody that does not know what precision/recall are)
I'd happily take a Bayesian answer if they preferred that, but that hasn't happened very often.
"just compose a team" sounds easy, doesn't it? Unfortunately there are lots of failure modes involving different parts of the team not really understanding what each other are trying to do, let alone what they are doing, and subtle errors getting by people who don't know what to look for. So, you can find such teams and some of them work well but a lot of them don't.
So an alternate is to try and find or create domain experts who mix all the appropriate skills, but this is hard and in the extreme case involves chasing down unicorns.
Companies and industries flop back and forth between preferring different approaches - right now a lot of people are talking about "data scientists" as one of the latter, but it will likely change over time as it always does.
It's a hard problem, and it shows.
> There are so many more statisticians who can at least communicate and work effectively with developers and vice versa.
Not in my experience. You need to design your data infrastructure to promote easy analysis, and you need to design your models to scale well according to the amount of data you're working with. There are also many cases where a project will require mostly engineering work for a while, and then mostly analysis/statistics work–there are ways to handle this with specialists of course, but there's generally a significant switching cost.
Also people with a combination of statistics & programming aren't that rare–IMO it's more that employers tend to search for both degrees, when instead you should be trying to evaluate the skills directly.
That said, most companies should probably be hiring data engineers rather than data scientists–for most "data science" jobs I've seen, almost no statistics is actually necessary/useful.
One is that there is buzz & excitement around "data science" right now. Nothing specific to this area, but in my experiences this creates a large number of under- or un-qualified applicants. It also creates an environment for companies to desire to hire a role they are not well qualified to hire for. It is really difficult to hire well for roles you don't understand well.
The second thing is that extremely few people are actually ready for this sort of job straight out of an academic program. A related Ph.D. or post doc plus a few years solid training in industry can make you a great candidate, but the academic work alone usually isn't even remotely close. There is confusion about this among both candidates (don't know what they don't know) and hiring managers (don't know what they are actually looking for).
Add to that an oversupply of academic credentials relative to academic jobs and you have a problem. If you are a large company with a well defined data science program and a defined "entry level" data science role, if you take skill development and training seriously and have the senior staff for it, well then you are fine taking strong academic candidates and turning them into talented data scientists. If you are a less experienced company looking for scientists to solve a problem you don't fully understand, you may be in for a pretty rough ride.
I've helped a few organisations solve this bootstrap problem by helping out with candidate selection and interviews, but many other just don't ask for help.