Very popular around her for a long time. Basically every family with more than one kid have had one at least fifteen years now. We already had one for difficult child. We didn't have any problems other than of course it didn't work well at winter, if new snow had not yet been cleaned well from roads. It also didn't work that well on dirt roads not at all at forest tracks. difficult child was easier to control with that than running around and of course worked well when he got tired of walking or simply decided he would not walk a feet more. Three years between them was enough that we didn't got twin strollers, like most people with two young ones. difficult child didn't like strollers any more at that point and he was very capable causing havoc also sitting in the strollers, so we went with difficult child either walking free or standing on the board. Of course there was days with me pushing strollers with one hand and trying to carry kicking, screaming and hand flinging difficult child in other armpit, but that is life when you have a baby and three-year-old (difficult child.)
Around here people use strollers a lot. Almost all babies sleep all their day-time naps in strollers either on patio, balcony or on the move. And people just walk more in general and especially people with small children. If for example day-care-centre or play-group or other place you are going is mile away or only little more, most walk. In town buses you go free with strollers (practicality reasons, because strollers are pushed in from middle doors and it would be difficult to go to pay after that and good advertisement for bus companies), so many prefer that for driving themselves and of course then have to walk to bus stop etc. As I said, if your kids are close in age, most get twin strollers, but after older one grows out of strollers or is already close to three when younger sibling is born, most people get the strollerboard. can't remember that I had heard much anything happening with them and wouldn't consider them safety hazard at all or at least any more than about anything else. Strollers themselves are much more of a hazard.
EDIT: Oh, and forget the 'skateboard ride', doesn't work like that at all. It doesn't stay on wheels if it's not attached to strollers and when it is attached (and especially if there is a kid on it), small kid can not easily push the strollers anywhere, it's even difficult for petite adult because you have to be so far from strollers when pushing and kid certainly wouldn't get any speed to it. And it does go only there the strollers are going and same speed. Strollers themselves of course are the different matter, easier for kid to push without a board so they get more speed, or putting your smaller sibling in and letting strollers go down the hill...