I just think this is more a hobbyiest or amateur approach to start a design
I agree.
I keep saying: PCB Layout is just a small part of the whole project. Same for Schematic - it is just a small part of something much bigger.
If you are designing simple boards, maybe advantages of professional approach are not so visible (professional approach may even looks like it is slowing down the whole project - e.g. generating professional manufacturing outputs may take same time as designing the board).
However, here are a few examples what may happen if you are not seeing the bigger picture:
- if you do not think about how components are going to be purchased, you my end up with board which is very hard to manufacture due very high minimum order quantities, very long lead time, end of life components. So in schematic a component may look awesome (it does exactly what I need!), but in reality it is extremely hard to buy the component and build the board. If you only think about schematic, you may not see that.
- of course, you do not need to include heatsink, screws, mounting holes in the schematic, but then when people are generating BOMs or during layout, they may forget about it - and they keep adding the components into BOMs over and over every time when they need to create new board variant
- when you design a lot of boards, you really do not want people keep asking you about your past projects ... e.g. what is replacement for a component (because they can not get the component which you randomly found on internet), what is order number for the screws which we used in prototypes, etc ...
People usually start to care, when they had to do a lot of these things by themselves and they know how hard or easy it can be if it is (not) done properly.