In a way you are correct. The problem was that he took a couple years to write The Privileged Planet, and during that time his scientific output dropped like a rock. Unfortunately for him, that was the period leading up to the tenure decision. Those deciding tenure got to see a pattern of diminishing scientific output from what appeared to be a once-promising scientist. Also hurting was his relative lack of ability to get research grants, him achieving $22,000 vs. the 1.3 million average for someone seeking tenure. He also had a lack of successful supervision of graduate students, only one completing his dissertation in seven years.
Basically, he blew all his time on ID and severely neglected his academic duties. It's no wonder he was denied tenure.
The Iowa Board of Regents assumed Guillermo’s guilt in advance, and denied his defense the opportunity to present evidence in favor of his innocence. Based on my readings of his case:
1) The Board of Regents would not allow into the record extensive e-mail documentation showing that Dr. Gonzalez was denied tenure not due to his academic record, but because he supports intelligent design.
2) They denied his due process rights throughout this entire appeal.
3) They refused Dr. Gonzalez the opportunity to present his case fully to the Board and to have face-to-face contact with the Board through oral arguments.
4) They refused to let him cite key NASA/Smithsonian Astrophysics Database information that shows how he outperformed many of the tenured faculty in his own department in productivity.
I believe that the arbitrariness of this decision to deny tenure will discourage people from accepting tenure-track faculty positions at the U. of Iowa (and probably also Iowa State U.).
The pretexts for denying tenure were that Gonzalez did not bring in a lot of grant money and did not advise a lot of graduate students who got degrees, but he did have a lot going for him: he was author or co-author of dozens of peer-reviewed papers, he co-authored an astronomy textbook that is used by his own department.
Those are the excuses I expect to hear in the preponderance of cases of Christians being denied tenure. Christianity won´t be specifically cited as the reason for its denial, threading through liability issues, so they come up with this other subterfuge.
Academics write books all the time. Christians though, who are clearly not wanted in academia, do so at their peril.