[dragnet2]

I’m not convinced this guy had to have a big motive behind this...People start fires just for the fun of it.

Correction: Some people start fires for fun because they're mentally ill. However some people start fires for political revenge, environmental reasons, to make themselves the hero, pay back, vendetta, revenge...Etc etc...

[DoughtyOne]

I think that was a given.

Fire-bugs do it for the excitement it causes them.

The others you mentioned are not true fire-bugs.