It's sound advice. Keep it facing backwards as long as it's practical and working for you and your child. If it starts to become a real problem you can turn forward at a very minimum of 15 months, but it's also possible to keep them backward facing until they go into the next stage which is high back booster. That is what they do in Sweden and they have excellent stats for child road passenger safety.
The longer you keep them RF for the better. If you were to be in a crash, the shell of the seat keeps their head, neck and spine all supported and lined up which is excellent at preventing serious injury. In a forward facing seat, the 5-point harness restrains their body but their head will be flung forward and the only thing stopping it is their neck and spinal cord, which can in rare cases cause catastrophic injury - the risk of this is higher the younger the child is, which is why it's illegal to FF in a modern car seat before 15 months. The other problem in a FF seat is that in certain scenarios, the child may hit their head on the seat in front, which is very unlikely in a RF seat because the seat acts as a barrier.
The vast majority of car seats on the market in the UK have the RF and FF limit the same - usually 105cm and about 18kg (17-20kg depending on the exact seat). It used to be you'd have a lower limit for RF (about 13kg ~2.5 years) but that is not typical any more.
Because we are used to FF in the UK sometimes people worry about things like legroom for the child or them being uncomfortable or not liking it, but IME if they have never been forward facing, they don't know any different and they will tell you if they are uncomfy (we found it usually helped to take off their shoes). In fact when you have children who are used to FF they tend to see RF as a novelty and "more fun" so I do think in most cases it's adult perception that the child doesn't like it or the child is seeing FF as the novelty because they are used to RF, and the adult takes this as meaning that the child likes FF objectively better.
The older they get the more the trade off balances so by three or so, I don't think it's a huge deal to turn them FF because you are sick of muddy feet for example. But for a younger child I'd want to keep them RF unless they are extremely travel sick or you need that seat for a younger sibling and can't fit a second RF seat in the car or can't afford one. And if it's working for everyone then you may as well continue as long as possible.
There are compact RF seats, RF seats with leg room, and affordable RF seats - but if you're trying to accommodate e.g. multiple children in a tiny car and both parents are 6ft tall and you barely have any budget and you need to buy the seat tomorrow - you're not likely to tick all those boxes at once. I don't think it makes sense to berate people for choosing to FF because everyone has to weigh up the decision for themselves. But yes, it does make a difference.