This does sound like overkill, but as I've gone on and flown different types I'd have to say the extended checks haven't been totally useless.
Of course no need to say pitch in fixed, or undercarriage down and locked in a fixed, but I've always been taught a checklist that will be useable in most things up to light twins, and I can't see too much wrong with it. It's practical and gets you thinking about things you will be using regularly down the track ..
Where it gets a bit full of sh1t in my opinion is when you have bored CFI,s who think they are training "airline" pilots ( as if their not gonna do their time elsewhere like everyone else) , and you have people pre PPL with two-three sided checklists ripped off from airlines a crapload of call and answer SOP,s and more waffly sh1t than you can imagine in the air that distracts from the actual practical art of flying an airplane from A-B safely. Sure SOPs are designed to save lives and create order, but when they do the opposite surely someone has to wake up?