people that think that way are usually used to reading things like flex magazine and only doing bodybuilder programs that work best for the pros. they require such massive volume for each body part that it does take many days to recover that part and allow for supercompensation. the other 99.99% of the world does not need the volume and can recover much quicker due to that.
it is common for strength athletes to train movements, not body parts, several times a week. an extreme example are the olympic lifters that train the bulgarian method. they will do their main lifts upwards of 10 times a week. yes, that means they do 2 a days with the same lifts. for most 2-3 times a week is good.
the trick is not train movements not muscles. it is more efficient for most people. you get more bang for your buck. for example, with squats you hit upper back, low back, glutes, hamstrings, quads, abs. where do you place that on a body part split day? back day? leg day? ab day? same with overheads, it works shoulders, triceps, abs, low back, and if you clean it from the floor the legs and hips to a degree. where do you place that? with body part splits you can go crazy with splits up to 10 or 15 body parts. do you train them separate or group some together. and how do you group them. you over analyze to a point of never having a program cause its just not quite right.
with a movement based split you can just use the main movements and get some extra work on areas that need, the weak links. this is where great programs like most 5x5 ones, 5/3/1, and other strength based programs. you can still gain mass, get lean, and do other things with those programs. for example 5/3/1 you just change the accessory work and your diet to fit your goals. the main lifts are the same for everyone. it works, its simple, and you can do it for years.
does that make sense?