-dik participle is non-future. I can understand that. But don´t you think the time definitions for -di-past are different? This was referred to even in the link you mentioned, si++.
Definition from: here
A nonfuture tense (abbreviated nfut) is a grammatical tense that distinguishes a verbal action as having taken place in times past or times present, as opposed to future tense.
The grammar of Göksel and Kerslake says -di past is *)the only tense that denotes absolute time in Turkish. And that point in time is past, that aspect is perfective (the action is finished). This is a quote from the book (sorry, I can´t remember if it was direct or if I edited it but anyway):
As for "that point in time is past", here are some examples:
- Ali nerede görebiliyormusun?
- Şu sağ taraftaki grubun içinde, üzerined mavi bir tişört var
- Evet gördüm (Time is the moment of utterance i.e. "now")
Or Ali is in the kitchen and his Mum who is in living hall calls him:
- Ali buraya gelir misin?
- Geldim (He has not come yet, but means I am coming right away)
"-(I)yor, -mAktA and -(y)AcAK are markers of relative tense. They denote absolute present or future only on the absence of another tense marker like -DI."
Thus, for instance what is usually called present continuous is actually not present at all, it is only continuous (imperfective aspect). If it talks about now or not is seen from the presence or absense of -di. This very much makes sense to me but I never discussed it with a native, I may be wrong.
*) Sorry, on second thought I think -miş past is the same.