Since when do dogmatists try to justify their conclusions with anything other than their dogma?
Dogmatists claim to possess the truth. They try to persuade people that it is the truth. If they simply wanted to explore the consequences of some specified hypotheses, then there wouldn't be any problem that I can see.
Isn't the dogma itself just a collection of foregone conclusions?
I don't know. I think dogmas can be rather complicated and somewhat interesting.
Why would this critically thinking student you describe give a shit?
A can think of two possible reasons right now and I could probably think of additional possibilities if you wish.
1. Suppose the critically thinking student is trying to earn a Ph.D. in theology. What if the people who evaluate the student's academic work are dogmatists?
2. The critically thinking student might want to communicate with beginning students of the dogma to help them avoid being deceived. A critical mass of people interested in the dogma is likely to be dominated by people who don't see and/or don't want to see flaws in the dogma. So a critically thinking student might have difficulty establishing an organization to preserve and build on the critical thoughts of the critically thinking student. There might also be difficulty getting into communication with beginning students of the dogma.
"Nothing upsets a Bishop as much as the presence of a Saint in the parish." - D. Quinn
That quote is new to me and I like it.
An additional point: we're likely to be more interested in what we think is true than in any one particular error. However, familiarity with actual errors can help one to avoid making similar errors. Perhaps a single organization could be dedicated to critical thinking (research and education) about a variety of different dogmas.