Yes and no, to an extent. In my opinion it all depends what you do with those loops and samples. If you just find a loop you like and stick it into your track without doing anything to it, then yes, it's kind of not your own work. But if you edit that loop - cut out the bits you want and don't want, add a load of effects in there that you think will make it sound better, cut and paste other samples/sounds into it - then it is your own. Change it to a point where it is hard to recognize compared to the original sound of the loop. Samples are necessary- most people don't have drum kits in their homes.