you are making a lot of wrong assumptions here.
first one is assuming that the price people are buying at is "quite high". obviously those who are buying don't share your views. and just because it is higher than a couple of months ago, it doesn't mean it is "high".
second is assuming that price would fall, specially assuming a big fall to $6k again. again just because it is higher now, it doesn't mean it will fall. it just means you missed the time when it was lower.
and actually this way of thinking is the reason why prices shoot up instead of having a nice slow rise like we have been seeing in the past month. people like you are not a small group. you are a lot of people! and thinking it will fall everyone of this group waits around to buy when it falls and when price never falls and instead rises higher and higher they finally give up waiting and rush in FOMO buying bitcoin.