According to St. Thomas, one of the reasons the contemplative life is more excellent than the active life is that the contemplative life consists in leisure and rest. The pre-industrial laborer generally had much more leisure time than we have today. The problem isn't too much leisure, but filling the time with things that debase us rather than elevate us.
I agree. It also depends on how you define "leisure". To me, leisure = free time, which is best spent on hobbies, reading, praying, learning, the arts, and yes...even entertainment.
Moderation. If someone uses "leisure" to sit around all day, that's just laziness. On the other hand, if you like to sit around all day, and you disguise this by "reading holy books" this can ALSO be lazy.
One could argue, as Thomas Walsh wrote in his book, that the 13th is the "greatest of centuries". It was the height of Christendom, the height of Catholic living and an ordered life focused on God. It was also the height of the arts, and architecture, music, stain-glass windows, etc.
Many nowadays would classify "the arts" as leisure. They might be right, as it's not physical labor/work. But leisure time is not necessarily laziness nor wrong. It all depends on what you're doing.