thing is, for alot of people it seems like when bitcoin price is "high" they think that means it is succeeding more than when it is "low". but if we think about bitcoin's intended purpose, it doesn't matter what the price is as long as bitcoin can be transferred peer to peer without any centralized party being involved. so if bitcoin was worth $1 people shouldn't complain.
The price is one of the indicator of bitcoin's success. What you're saying is totally right, bitcoin will be continued to be used even if it was at $1, but if something goes down from $70k to $1 then it also means that somehow it has failed. There will be people who will keep using bitcoin but forget mass adoption at that point.
Then of course are also people who took the risk to buy bitcoin I can totally understand if they want to get some profit, nothing wrong with that.