This sounds extra strange. Diplomatic victory has always been (and still is) about accumulating diplomatic points and not influence. Sadly I had a savegame spring clean and the latest game I have right now is turn 60 on normal, but I took a look and the closest AI to diplomatic victory is 12% in. So that sounds like a bug or a mod or something that you're experiencing.

As always, could you upload a couple of save game files ?

This way, people can make a much better assessment of the situation.

Well I didnt mean to point out a bug or anything (I said influence points but you are right its Diplo points, just mixed up the 2), just telling that Diplomatic Victory is way too easy and quite stupid in my opinion. I mean why should a random faction I encountered 10 turn ago would have that much politic power that it would just stop the game and say "I won this boyz" ??? 

I really thought diplomatic victory was about being allied to all other factions, I even remember having a discussion long time ago on the forum about how easy it was for Drakkens to force everyone into alliance with them or something like that, but maybe I have wrong memories ^^ 

Else dont you think Diplomatic victory should be linked to.. diplomacy ? And not to some point you earn by doing any action with any faction.

Diplomatic victory is not easy and not "stupid", and it does take work. You do have to be allied with people and you have to make treaties with people, and it takes a lot of time. I don't see any way to achieve it on Normal in 80 turns. Are you playing on Fast? Are you playing an "overstuffed" map, like a Small map with 6 empires? Did you check if the AI that won had alliances with all other AI factions? 

Because either this is a bug and then you do need to include a savegame, or you played on Fast and for some reason all your AI were weirdly peaceful and allied with each other from the start and maybe researched the end-tier diplotech? (I personally only ever had Drakken or Wind Walkers AIs propose alliance on their own, and sometimes Allayi, so maybe if you had only those factions spawn?). You really cannot (or at least should not) win by diplomacy "suddenly", it's a late-game win. 

Also as the Allayi you are the most suited for exploration right from the early game. If you're still meeting people turn 70 while playing them it's just not playing to your strengths. 

diplomacy victory always been a late game victory for me. even doing it on fast i did not experiance a diplomatic victory. 

but no, you never had to be allies with every one. but it does help a lot.

without savefile we can't say anything more about it.

The only way I've been able to get a diplo victory is by turning every other victory type off.  I always wound up accidentally winning an economic or science victory before I could get enough DP to win that way.