on what the Buddha taught
Suppose a friend is helping you cleaning your new house. When you head to the store for some supplies your friend starts with the hallway floor. It is an old nice looking marble one. After the mopping your friend takes a break.
When you return and start to clean the same floor, your friend tells you that it had already been cleaned. But when you explain that the marble is actually white and what was taken as the pattern was in fact dirt your friend might look at the floor differently. Especially after seeing that with the proper cleaning tools these "patterns" do indeed come off. So now it is better understood what should have be done right? When your friend didn't see the floor as white there was no problem seen in leaving the stains as they were.
It is the same with the mind really. In the Aṅguttara Nikāya we find these two texts:
'This shining, almsmen, mind. And that now is stained from visiting stains. That, not having learned, the commoner essentially not understands. Therefor, for the unlearned commoner, cultivation of mind is absent I say.' (AN1.51)
'This shining, almsmen, mind. And that now is liberated from visiting stains. That, having learned, the hearer of what is noble essentially understands. Therefor, for the learned hearer of what is noble, cultivation of mind is present I say.' (AN1.52)
So, in this way it is not a statement about the mind being beautiful as it is, perfect in its nature, that it only needs to be observed, or anything like that. No, even a clean floor is still just a floor. With the dirty floor it was about not seeing dirt as dirt and thus lacking the knowledge, effort, skill, interest, to attain to the job of removing the dirt.