Sure, sometimes it is not easy, e.g. using the metro ("underground") in Saturdays or Sundays is quite uncomfortable. However, that allows to avoid increasing ticket prices, because of optimal utilization. So in the end, a bit of discomfort during 3 months for getting very cheap public transport during the whole year is a good deal, in my opinion, as there is no such thing as a free lunch [1] :-)

[1] https://en.wikipedia.org/wiki/There_ain%27t_no_such_thing_as...