Interesting that they cite California's long constitution as a problem, since Texas is in the exact opposite position as California (budget balanced), and yet has a longer constitution (second only to Alabama).
This is the same case in Texas.
It's the fact that it is both long AND convoluted that causes the problem. Convolution is the major problem. Length makes convolution much easier to pull off (How complex can you really make a 1-page constitution?), but it doesn't guarantee it.
That said, Texas's may be just as crazy, just in a crazy way that somehow works. That's unlikely though. It's pretty hard to make an extremely complex governing document that will stand the test of time and still function properly as Texas's apparently does.