It is not always easy to determine the entry point. I agree with you on this. But nothing is impossible. If you constantly study trading and improve your level, then your trade will bring you profit.
Studying the trend for most altcoins might not be that easier as you think. When dealing with such, you should think of some risks that you might encounter. This is why my preferences is always with bitcoin and some other well established altcoins, because i know that no matter how much they dump, they will one day still come up and i will get back my money, if not additional profit.