Kurdish is also Indo-European, but that doesn't stop Turks claiming it's just a dialect of Turkish (mountain Turkish).
There are some shared vocabulary, but thats pretty much it. Kurdish is much closer to Farsi.
Back in the 90's, it was not that hard to find Turkish people saying exactly this.
This was before most had the Internet, so they could say stuff and get away with it. The idea was to belittle the Kurds, and deny them their identity. Obviously, not serious scholarship.