They have done it for years and it doesnt seem to be slowing down. What suprises me is that some Brompton owners have multiple Bromptons.
If thats true (as in if you have stats to support that comment...despite quoting their move to a new, larger factory. There may be some underlying other reason predicating that as well) that doesn’t mean it will/can continue.
Most bicycle enthusiasts are multiple bicycle owners, Brompton owners are simply a part of that same subset.
I own 3 bikes atm, all folders, and only one Brompton. I dont desire another*, and adore the one I have.
But...it’s not perfect, nor without areas which could be refined.
(*I’d like a Moulton XTB truth-be-told. And a Rivendell. And a mini-velo. And a....)
Brompton offers essentially the same, single product it started with some 40 years ago, and nothing more. Certainly the bicycle business has and continues to change (the introduction of an electrified Brompton is a step forward though, but it’s still intended to serve the same niche of the market the standard one is) and most manufacturers respond to those changes by broadening their offerings.
The demise of the likes of Eastman Kodak and Polaroid come to mind as single-focused (no pun intended) companies which didnt embrace changing tastes in photography or not soon enough anyway to stay viable after being at the top of their games.