People are invested in bitcoin in many ways.
They see good reasons to stick with it and most of them are thinking long term.
Things crash from time to time, it doesnt mean they are dead.
And besides that profit isn't the main focus for most of the old dogs of bitcoin.
I think people still buy Bitcoin because it still has a lot of good left in it. In terms of an investment asset, although it has always been swirled with negative news, it is still a profitable kind of investment, and so, people keep on putting their trusts on it, and in turn, they keep on investing to it. I think that as more and more people are starting to see the good things that Bitcoin investments can do and bring, it somehow purges the negative ideas and doubts that people have over it that helps it gain more popularity.