Of course Tim has no clue about feeding the baby or doing much for the little kids, it's obvious the lazy man never does anything to help out - that's Hella and Hosanna's job - taking care of toddlers and babies in the household. Tim cannot be bothered or they probably see a mean side of him.... We see his constant controlling of all family members and situations in front of camera. Ella has admitted many times that he makes all the decisions (even not allowing them to "temporarily" bring the kids beds, table and chairs to the new house - ridiculous)
Of course Tim stays in his office with his comfortable chair, desk, tv, video games etc. & prob. no one is allowed there but him.
When Ella said it would be too much trouble to get out the blender, then have to wash it and put it away - she prob has Hosanna clean it anyway - awful excuse... then bragging to her kids that she just chews the baby's food instead & how she used to feed food from her mouth to her son -- just nasty and gross