Personally, I think the poppy meant the most to a particular generation - immediately after the world war one at a time when it directly affected those people. Now, for my generation, and probably yours too (I'm in my 20s) the 1st world war and armistice day do not have a direct personal connection to us. That doesn't mean I don't care - I've watched documentaries, read books etc and it's very sad especially when you read individual stories of soldiers or people left behind. I also recognize the sacrifice that people made and I appreciate that I probably wouldn't be here without that. The same goes for WW2. But as years go by, the sadness becomes less personal as directly affected people pass away. The Armistice agreement was signed almost 100 years ago.
So although I recognize that I probably wouldn't be here without the sacrifice of the men/women who fought/died in WW1/2 I also wouldn't be here if the Romans/Vikings had murdered my ancestors...but I don't wear anything in particular to pay my respects to them because I don't feel the need to - based on having no emotional closeness to those people.
Bonfire night is a good example - how many people who went to a firework display or who had a bonfire this month did it because they were celebrating the survival of King James the first? I doubt very much that anyone was going to see fireworks other than for the reason of watching some nice fireworks. It just doesn't mean anything to people anymore - and that's normal, a lot of time has passed.
Similarly, I don't think that people born from around 1980 onward really consider much when they buy/wear a poppy and if they do, they probably consider those who have died in Kosovo/the Falklands/Afghanistan/Iraq more than the 1st/2nd world wars - since they are more likely to have lost a family member/friend from those conflicts.
I remember watching 9/11 unfold on the TV when I was 11 and I've never been able to accept people's jokes about that event or to accept people's dismissal of it. I always think about it every time the anniversary comes around and it does haunt me and has affected my outlook on the world/life. But I know that there are people born after 9/11 or not long before it, who have zero emotional connection to it and who don't concern themselves with a minute's silence etc. I don't think that's wrong of them - it's just due to the fact that it didn't really affect them and they have no direct memory of it. I certainly wouldn't shame them into wearing a commemorative flower and it's certainly not expected for TV personalities to justify themselves for not wearing anything to commemorate it....if you see what I'm saying here.
I don't believe that people will wear poppies in 100 years time. Time moves on and the people to whom certain events and sacrifices meant so much also move on.