For me, it's all about the individual at the garage. I've kept going to the Suzuki garage where i live now (despite no longer having a Suzuki) because they remember my name, what I ride, and what bike I'm lusting after next.
The dealer market's changed a fair bit since I came out of the trade in 2015. A lot of dealers are relying on PCP (essentially leasing bikes on a monthly rate for fixed period, after which time they're either bought outright or traded in) or finance deals that they then take a percentage of. Margins are really tight, especially for the big four, and the Taiwanese brands are snapping at their heels at the lower end of the market.
If a dealership wants to survive, they can't rely on litre sportsbikes alone, nor learner-legal stuff alone; they need a full range, and need to cater to as many different customers as they can get through the door. The older riders of the golden generation are beginning to get towards the end of their riding lives in many cases and the high-value bikes that they bought need to be bought by younger customers. However, you can't get new people into the system without... a good learner range. And if you want people to buy your high-end products, brand loyalty is a big thing; you want to get them in on your learner-legal models, and retain them.
Until a few years ago I would have said I was Kawasaki to the core, but now I'd say the same about Suzuki - which is all the direct result of a positive dealer experience with the only new bike I ever owned, a 110cc for two and half years. Now, I'd go back just to buy from that dealer again.