People even started taking loans for their honeymoon and things but that's not my point here.
You are missing the point, those comparisons are the point that he is trying to make. Otherwise why mention people taking out loans to buy a car? It is not relevant to the question unless he wants to make direct comparisons.
What if the bitcoin price crashes after the loan is that person capable of paying it back along with the interest?
Nothing? You are not paying back the loan from the invested Bitcoin. You should never take out a loan that you can't pay back in any case so there is no problem here. Worst case the money is lost and you pay back the loan as originally planned. The whole world practically runs on debt, and people here shy away from it like it will instantly ruin your life. This does not say good things about the experience of users here.
Investing our money is smart choice rather than spending it but I don't have the same opinion if someone is taking loan and want to invest.
As I said, there is nothing wrong with this compared to the most reasons why loans are taken. It is much better than most of those reasons. Don't make it out to be something that it is not.
But you are missing the point too, the one who is taking a loan will be hoping to make profits from the capital and pay back the loan so there is no plan B if bitcoin crashed which is what I am raising what it is. An average middle-class joe spends his entire life savings to pay the mortgage for the house he wanted to have and if the plan fails then this is another trap that may end the dream of getting finanical freedom which is why I said it is no different and we need to follow the process save=>invest=>ROI=>loop so even if the growth looks small that comes with no risk and you don't realise the power of compouding which makes it much bigger in the longer run.