However, I wonder if there might have been sometime appealing about the work of a shepherd for Jesus. Certainly, Romantic writers have idealized the life of shepherds in their poetry. Do get me wrong, being a shepherd is full of difficult challenges and times of high stress, but if the shepherd cares about his flock, then those tough moments are certainly balanced by getting to watch the antics of these sheep he cares for.
It also does not require a lot of micro-managing. The sheep generally know what to do; only occasionally does the shepherd have to deal with a particularly foolish or stubborn sheep. More often, the shepherd's role is to protect the flock from external threats, particularly predators.
Jesus looked at the crowd and knew that they were sheep in need of a shepherd. He could see the predators who preyed on the sheep. He could see that the sheep were lost and confused, needing the guidance that a shepherd could provide. Despite being weary and wanting to get away, Jesus decided to take up His role as shepherd and be their (and our) protector.