Not all creationists are like this. You, for instance, come back with well-researched responses (which is good because it keeps me on my toes). I only revert to my frustratiin lexicon with medved (for his spamming and his inability to double check his "theories"), gore3000 for his inability to see anything posted to him and then claiming that no one answers his questions, and f.christian because his posts are incoherent. My "ad hominem" attacks against those three are usually liberally sprinkled with references to research or attempts to "run the numbers" to see if what they are claiming is feasible.
I would love it if my kids could have attended a high school that allowed or encouraged rip-snorting debates over philosophical and religious issues, but there are limits to what is debateable and what is time-wasting.
Okay to being frustrated with someone not accepting your evidence.