Lee, that's a very logical supposition with sound reasoning. Like an earlier poster, I don't find this story amusing. But, the two shoppers who subdued the man and extinguished the flames (suffering their own burns in the process) are brave and impressive individuals. Prayers to them and their families for a quick recovery.
Here are some clues to let folks know that this wasn't your average nut case:
1.) The use of cleaning chemicals, which apparently the FBI has wind of through their monitoring of communications, since a warning scrolled across the Fox News screen.
2.) The lack of identification, delaying search warrants on his home and arrests of co-conspirators.
3.) The choice of the target, involving children, shopping (economy) and Santa Claus, a symbol of a Christian holiday. (Yes, I know Santa Claus isn't a religious symbol, but to Muslims the distinction might be too difficult.)