on what the Buddha taught
Suppose someone is helping a friend cleaning up their new house. A lot has been done already and only some floors are left to do. When their friend goes to the store for some groceries, they decide to start on the old hall which has a nice looking marble floor. After mopping the hall they take a break.
When their friend returns and, to their surprise, starts to clean the part which just got cleaned, they inform their friend they had already been cleaning there. When their friend explains that the marble is actually white and what they probably took as the pattern was is in fact dirt, they might look at the floor differently. Especially when seeing that, with the proper cleaning tools, these patterns do indeed come off. Thus now it is better understood what to do right? When they didn't see the dirt as dirt, they saw no problem in stopping where they did.
It is the same with the mind really. In the Aṅguttara Nikāya we find these two sermons:
'This shining, almsmen, mind. And that now is stained from visiting stains. That, not having learned, the commoner essentially not understands. Therefore, for the unlearned commoner, development of mind is absent I say.' (AN1.51)
'This shining, almsmen, mind. And that now is liberated from visiting stains. That, having learned, the disciple of nobleness essentially understands. Therefore, for the learned disciple of nobleness, development 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. A clean floor is still a floor. With a dirty floor it is about not seeing dirt as dirt, and thus lacking the knowledge, effort, skill, interest, etc., to attain to the job of removing the dirt.