My point is that just because a compound is simple or easily understood doesn't mean it is safe. What if excess phenylalanine is toxic? It's not completely outside of the realm of possibility.

For the record, I agree with you that it is unlikely that aspartame is toxic and the only studies that show this use non-human analogues. It is, however, important to play devil's advocate in scientific settings.

I read some study that aspartame changed the gut flora. Sugar probably does the same thing though. But sometimes there's interactions that science forget to study