Small coins usually do die. Its pretty much a gamble.
There is a reason these coins are low difficulty, and its either because they are new, have no following or offer nothing special.
I've gotten lucky on a couple but most haven't worked out.
Yes, low difficulty coins are completely waste for mining because we don't know how far they will show their potential in developments. If they are very active in developments will help the coin to increase its value that's why we should always research before mining any coin whether it is new or old.