You can see quite clearly how Gregor feels about his job in the first section of this excellent short story. When he wakes up and finds himself transformed and struggles to get out of bed, he expresses clearly his overall reluctance at going to work and his dislike of his job. Note what he says:
"Oh God," he thought, "what a strenuous profession I've picked! Day in, day out on the road. It's a lot more stressful than the work in the home office, and along with everything else I aslo have to put up with these agonies of traveling--worrying about making trains, having bad, irregular meals, meeting new people all the time, but never forming any lasting friendships that mellow into anything intimate. To hell with it all!"
We see if we read on in the text that Gregor's main reason for working in his profession is to support his family and help them out financially. Yet his job does not give him meaning or purpose, as we can see with the way he complains and his specific problems with his life at the moment. Thus Kafka makes serious comments about the impact of lack of purpose and fulfilment on humans in this story.