Jainism, as opposed to Hinduism, is a fact-based religion wherein the structure is framed around what is known, rather than what is not. For example, Jains would say that Hindus do not know from where their scriptures come from, or if they are even of relevance of morality and religion. As opposed to Jains whose monks have kept a strict record of study or religion and morality.
Jains are solid architects in history, and the religion is itself a peaceful and beautiful one in general, but they don't compare to Hindu architecture in history. The reason that Hindu architecture is better overall is because of the sheer scope and longevity of the long term Hindu architecture's legacy.
I think that Hinduism is definately more structured that Jainism is. Also, I if I am not mistaken I think that Hinduism has been around a lot longer, so they have had more time to figure out what works in their religion, and to remove all processes that do not.
I personally think that Jainism's architecture and Hinduism's architecture has something behind each of their artwork. I personally think that Jainism's architecture and Hinduism's architecture has led them to sharing ideas as well as thoughts that they had to share amongst other people. I personally think that two people doing artwork could be how they felt or feels about situations that they might be going through or went through.
I would not respectfully rate Jainism's architecture as better than Hinduism's architecture. Both of these styles are very similar and share many of the same traits, so much so, that the common person may not be able to tell the difference, so I do not believe one is inherently better than the other.