To summarize my in-game experience (getting from stock sidewinder to cobra and testing various activities) and the impressions from reading forums.
1. ED is and always been a 'oldschool' game. New players are thrown into unfriendly world almost without knowledge on how to survive. Sure, there are tutorials and manual, but to actually 'win' you have to learn A LOT of information from wiki, forums and watch a lot of youtube videos. Some players complaining here are clearly not gone through that process of passive learning. In a sense, they must 'git good', but it's not some in-game skills, it's passive knowledge like 'do X to get Y', 'if you want to avoid X, don't do Y'.
2. ED has perfectly fine gameplay for new players. As a 'twink' commander, I've got from stock sidewinder through hauler to mostly B and D-rated cobra, had tons of fun doing it, and it wasn't in any way 'hard'. Only two interdictions outside of doing missions, both times I was carrying cargo. Easily evaded first (in a hauler), submitted to second (in cobra). It was a novice Viper Mk3, shieldless. I decided to drop some cargo for the fun of it, but apparently not enough, and already lost one ring of shields while messing with UI. After that, I just boosted away. Police appeared in 10 seconds. Escaped with shields still online. If I had beam lasers and A-rated components, I'd torn him to shreds. Also dropped to two 'weapon fire detected USS threat 1' — everything was just as expected: some wanted ship, with police scanning and then attacking. Both NPC were lower ranks, first with Asp Scout, second in unshielded Vulture. Both times I assisted the police, and AI worked just like expected — maybe a couple of shots fired at me, enemy went down easily.
And it should not matter if you are novice with ~3000000 total assets or a triple elite with billions. If you're flying D-rated Cobra in high-sec Imperial system doing lower-rank missions your experience should be the same as above. Any AI above dangerous has no 'reason' to attack you. They should be looking for bigger and juicier targets, so you should be free to go about, occasionnaly killing some dumb newbie NPC that is after your 16t Biowaste 'juicy cargo'. But if you intentionally go to high-threat USS, Haz-RES, CNB, do high level missions — high-level NPC have every right to kill you like a nasty fly. Low-sec, anarchies — it should be a whole different story. But even there, elite pirate lords should not chase you for juicy biowaste. 200t of free gold — maybe, but not for lower-value commodities.
3. Something is clearly wrong for old non-combat players. Some of it is due to old knowledge no longer working. And yes, in that part, we have to adapt. Go out exploring with good shields, thrusters and maybe some armor and beef up jumping range by using engineers. Put some good shields, turrets and mines on a trading ship. Some of it is clearly due to bugs and/or hidden variables that weren't causing great harm before, but doing so now. From reading other posts here and from my experience these are key issues:
a) same NPC re-interdiction after running away. Even if the police was at the scene of crime, and already was firing at said NPC.
b) NPC get overly attracted to PC when they have no sensible reason to do so, like elite pirates going after some 'juicy' cargo that is clearly low value and not worth the effort.
c) NPCs aggression towards PC without any sensible reason. Sure, there should be terrorists and lunatics, but not that many of them. Especially in high-sec systems, where they should be basically nonexistent.
d) overall frequency of interdictions. It was probably tolerable in pre-2.1, where most NPC interdictors were killed by players, but not in 2.1, when running away is more frequent, due to issue a)
e) high-level powerplay ships harass players too frequently. Again, was probably tolerable in pre-2.1, but not in 2.1 with improved AI.
Essentially, if player isn't asking for trouble, he is not getting trouble. Оn a very rare occasion we should run into psychos, terrorists and very angry elite pirates while doing some mundane things and not attracting hostile NPC by doing something wrong, like hauling a full hold of painite in unshielded weaponless T7. And there are enough anarchy systems, haz res, CNB, warzones, high-threat USS and Elite-ranking missions for those who ask for trouble.