Anyone check if one of the hundreds - probably thousands - of boys abused by priests in France dropped the match? How about some of the nuns kept as sex slaves for priests in several French religious orders? This isn't just part of the past few decades of revelations, but highly current in France. Just in the last month, a French cardinal has been in court for his own abuse and coverup of others, the nun slavery has been the subject of a television documentary, and French clergy have tried to block release of a documentary movie about the abuse scandals.
Or maybe the fire is a highly convenient distraction from all of this - suddenly, world sympathy and hundreds of millions of dollars are flowing in. Before you laugh dismissively, hasn't it become clear the church leadership will do ANYTHING to defend itself? Convenient how all the art could be saved.
Odds are, probably neither of those causes, but an accident - which some call an "act of God". So if God made a symbol of that church burn...isn't it time to take the hint??