As far as I know, they are not exactly breaking the rules, but Pokemaster is the only one who can say if they are breaking the rules
"Only answers in the answer box: Use the comment function to reply to others' posts, for example to ask for clarification on a question/answer. If you need to add to your own post, click edit to change it."
~The [Rules][1]
To my understanding, comments are more of opinions, not facts. People put their answers as comments because they don't know if they're correct. If they did answer their thoughts in the answers box, they could be giving someone false information.
Also
Suggestion questions aren't for us regular users to answer, since Pokemaster is the only one who can make changes to the site, Pokemaster decides whether or not the suggestion turns into an actual thing on PokeBase.
Source:
Knowledge
[1]:
http://pokemondb.net/pokebase/rules