Firstly, ED isnt an MMO, its MP functionality is severely limited and can be described as "functional".
Secondly, i never said 100, 100 is a stupid figure. Back in 2003 i was playing Eve with 4k people on 1 server, it only ever got laggy when fleet fights the size ED could never see occurred. By 2007, on decade old internet connections and infrastructure Eve servers were holding 10k players, with ease.
Now, Eve-Online server can hold between 30k and 40k players at any one time (probably more if more were playing). People need to stop making excuses because we now live in a world where we can do amazing things with servers, and the average consumer has the same internet connection as server providers used to host up to 3 Counter-Strike servers back in 2002. One server isnt just "1 server" its backed up by Nodes to ease the load whilst still having 1 big playground for people to play in.
With EDs number, everyone could fit on 1 server...Maybe 2 on a good day...P2P was chosen either due to time or most likely; financial constraint i guarantee you that. If im playing a MASSIVELY Multiplayer Online Game i expect to be able to play with a MASSIVE amount of people, and in ED you cannot.
I dont care about how the definition of MMO can be interrupted due to its vague acronym, there is nothing massive about the multiplayer features in this game.
Any comparison with EvE makes no sense, as it is a very different game with completely different network requirements. Even then, with many people on, its framerates drop dramatically. Someone once excitedly sent me a video of a massive EvE battle. I couldn't believe what I saw: essentially a completely static images, with every few seconds some minor laser fire. No thanks.
And I do this from time to time, so don't feel bad this is on your post, but P2P allows us to connect with players from around the world. I am in California, and have been in instances with people from the Americas, ANZ and Europe at the same time. That is remarkable, especially in a game with 6 degrees of movement at high speed.
Just to repeat: (note, this is about latency, not bandwidth)
Client server
--------------
Player A: California
Player B: Japan
Player C: Europe
central server: UK
Player A ping to server: 120 ms
Player B ping to server: 200 ms
Player C ping to server: 20 ms
Result:
Player A connects to player B with 120+200 = 320 ms latency
Player A connects to player C with 120+40 = 160 ms latency
Player B connects to Player C with 200+20 = 220 ms latency
In P2P - server is only used for transactions, not for players, so
Player A connects to player B with 130 ms (ping between CA and Japan)
Player A connects to player B with 120-130 ms
Player B connects to player C with 120-140 ms
People who don't understand networking think that C/S is somehow the holy grail that will fix networking issue. It will not. It will in fact make the experience worse, or end up with regional servers.
The reality is that most networking in ED fails because people have poor or misconfigured internet connections. You can improve things already to set up a fixed port config, and make sure UDP is allowed. But client-server architecture (which is not going to happen anyway) will not solve poor internet connections of players.