PES 2017 sold better than PES 5, in fact the last three versions of PES have sold better each year since 2015 compared to any previous version of PES.
PES has never flown off the shelves, it's always been behind FIFA in that regard. We can remember all the amazing parts of PES 5, we can remember how much fun it was when we first put the PES 3 disc in our PS2 and played Charmatin vs. Trad Bricks for the first time. The truth of the matter is that PES is getting better, it had a major lapse when it first hit 'next gen' consoles but these last three iterations have been getting better and better and better.
We don't know yet how this game is going to play as a final result - we're playing an online beta that is maybe very different to the finished product. But it's still a fun game. If this was the game that they released, I'd happily play it for a whole year.
Bear in mind that PES 5 came out when you were 20 as well - different frame of mind for playing and indulging in games compared to now.
Ok I give you that BUT games like PES17, and bellow you can't deny and say they are PES greats like PES 5 or PES 13 that in 2017 these games are still being played, still have pretty strong community. What I'm trying to say is these games get wuickly forgotten while PES5 esp WE9LE will always be played even 10 yrs from now. 15. Who knows. Just like SWOS and Kick Off 2. Another example is FPS games. Take all FPS games today and they can't even sniff the success that Counter Strike 1.6 had and STILL HAS to this very day, including Source and Global Offensive. Certain games are meant to be cemented in the hall of fame and those are PES 5 WE9LE PES 13, ISS 98, Kick Off 2, SWOS 96/97. Just like movies. They can make a great action/crime thriller now with great actors/ special effects but nothing can ever touch Scarface or The Godfather. This is the best explanation I can think off and I think you'll agree with me as well.