I'm not too surprised to hear that. In fact, I'd say a top score on Kaggle is probably a pretty positive indicator. Yeah, refining the model probably isn't as big a deal in a real project as it is on Kaggle, but it still takes some decent chops to get a good score like that.
My best was somewhere in the top third, so I'm not an especially strong Kaggle competitor. But even that took a lot of data parsing, piping, cleaning, moving some things to a database, populating a model, and parallelizing the processing so I could things on a cloud in an hour rather than 100 hours on my laptop. I learned a lot from it.
If you can score high on Kaggle, you definitely have some skill. And it's hardly like people who can do this never have the other skills necessary to manage the other stages of a data science project.
I probably wouldn't hire someone purely on Kaggle scores, but sure, it's a positive indicator of programming and data management ability.
