Probably because they have consistently been putting out "game changer" cameras starting with the A6000. Sure, the competition quickly catches up (and surpasses in many ways) Sony's offerings, but know one cares about a catch-up story. Sony knows how to make a splash and get people talking about them.
Samsung was first, but Sony has been relentless with pushing MILC. I'd say they've been putting out "game changer" cameras well before the A6000. I had an NEX-5. It had no built-in viewfinder, clunky menus, slow CDAF, and didn't challenge DSLRs in a meaningful way. Small body, kit lens with good OSS, and decent 1080P video were the highlights.
Bought the NEX-5N after. Better noise performance, and electronic first-curtain shutter. Low light performance up there with the best APS-C DSLRs of its time, low shutter lag, still hopeless menus.
Then the NEX-7 with SEL24F18Z and my peers took notice. The designers raided the A-77 parts bin and gave it a 24MP sensor and OLED EVF. Alpha shoe for flash and triple-dials. All buttons on a camera should be customizable IMO, and the NEX-7 indulged.
Sony doesn't seem to care about cannibalizing their other lines, and just put out cameras with whatever new parts are available. Like the mad RX1 and RX1R full frame oddities with fixed 35mm lens. It was expensive, had no OVF/EVF, and slow AF. A friend of mine had it, we marveled at the tech but shooting with it kind of sucked. But development no doubt helped pave the way for the A7 line.
They sell FIVE different versions of the RX100 simultaneously because Sony designers can't stop iterating.
As someone who jumped from an NEX-7 to a A6500, I appreciate the rapid progress. There's nothing I'd want from an APS-C DSLR, and it's nearly the perfect camera for my needs.
Menus could still use work though. Sony seems more focused on advancing camera tech than photography.