Carmen can't get much of anything from a sippy cup. She's always had difficulty getting milk from anything but a fast-flow teat, and the no-spill type of sippy cups require some technique to drink from. During the day, she drink from a cup with a lid and straw, because it's easy for her and it's really the only way she can successfully 'feed' herself a drink. But when she's tired and just wants some milk (she still has toddler formula since she's not a big eater yet) and a cuddle, we use a bottle since her cup and straw would spill all over if I tilted it for her.
All babies- and toddlers- are different, and it's impossible to make an accurate blanket statement about what they "need" or not. One may not see a reason for their own child to use a bottle past the age of 1- and that's fine for them- but surely you can't make the same judgment for someone else's child!
As for the article, there were a lot of assumptions made about bottle-feeding mums, that completely led away from the research in the first place. They haven't reported any good argument that the bottle itself leads to obesity- only that over-feeding, giving sugary drinks and putting rusks in the bottle might!