I know there's languages out there that don't use aspect much if at all (such as German), but personally I just like the distinction between habitual versus non-habitual actions.
This, however, creates a minor issue in my conlang. I don't really see much point in my conlang having a perfect. It has relative tense, in fact, there's a total of 5 different relative tenses to choose from, which means that there's functionally 5 different past tenses. Well, remote pasts anyway, there's also a recent past, but details... Anyway, with my past tense being this detailed it would seem that having a perfect/imperfect distinction would be redundant. To me, it looks like the only reason you would have such a distinction is to indicate to the listener whether or not what you're describing to them is part of a longer sequence of events or not.
Of course, looking at natural languages, I can't seem to find any indication of a language with aspect that doesn't include a perfect/imperfect distinction. Also, I believe that the habitual and progressive are considered sub-types of the imperfect, which means that such a conlang would functionally have an imperfect but no perfect to contrast it with, which would be rather strange. Well, technically my distinction is more habitual/non-habitual, but eh.
Of course, I'm not interested in making a naturalistic conlang, but in my view, if there is something no natural language does, there's probably a very good practical reason for that.