The primary or initial reason why most people invest is for profit making first, then come other reason(s). Though there are people that do not like keeping money in Bank because of bank wahala and EFCC problem. There is an amount of money you will have keeping it in bank will be a very risky option and in that situation the only best option is to look for where to invest it, so that you won't be questioned because I have seen alot of people been questioned, not only questioned they freezed there account because of the amount of money in their bank account.
they are investors and of course, like you and i want ROI. a quick profit in investing and the good thing about altcoin investing is that even the smallest amount you got can become the biggest profit maker in the bull run.
however, a few religiously believe in the cause of the altcoin. before Bitcoin was further debated by its size and some other issues, the community was very devoted to decentralization and some even were making BTC as the power for the revolution against the empire.