Answer: It's important to only use credible sources for academic writing because it can lead to a non-factual or false argument. Your audience would want reliable, trustworthy, up-to-date and overall factual information.
Explanation: Without reliable sources to include into your argument, you will otherwise come up with a false conclusion, with unreliable evidence to back up your claim. Another thing about reliable websites is that while most websites that end in .gov or .edu are reliable, some of them will use those suffixes to mislead. Which is why it is important to do your research first.
I hope this helps! :)