Why was the Black Death a good thing for some people?

Between 1347 and 1352, the Black Death wreaked unprecedented havoc on the population of Medieval Europe. This outbreak of bubonic plague, however, was not bad news for everyone: agricultural labourers, for instance, gained much from this catastrophe. According to Utah State University, the population decrease, which historians estimate at between one-third and one-half, meant that the "nobility had difficulty securing the necessary workforce to sow their fields and harvest their crops." (See the reference link provided). This meant that agricultural labourers could be more selective about their working conditions: they had the opportunity to take over land which was previously occupied by plague victims, for instance, and demanded better wages because they were fewer in number. 

We see the impact of this change through a Sumptuary Law which the English Parliament introduced in 1363. This law came as a response to the increased wealth of labourers and sought to curtail their newly-found freedoms by dictating how they dressed and what foods they ate.