The idea of free energy is the same.
I would like to disagree here. Free energy is not the same as free items. I could have 1200 advanced solar panels (or lv-arrays, your choice) generating a whopping 9600 EU/t, and yeah, that's crazy for free power. However, I can't Spend all 9600eu/t in seconds, nor can I spend it on whatever I want. It's quite visible in GT with the changes to the Mass-fab to MatterFabricator, and rarely do I find people arguing against that specific recipe, but we'll just leave the rest of GT out of this convo. In fact, if he released a matter-fab only mod, I'd imagine it would get lots of use.
Where EE2 broke boundries was the energy condenser and Klein star, not the energy collector. Let's be honest, you turned gunpowder into glowstone? Or Aeturnalus fuel? Good for you! Now what to do with it? All you could really do was make more Klein stars or more coal. We already do the same with Lava from the nether, or a forestry/railcraft biomass farm. I mean, you 'could' follow the really long process in IC2 to make a diamond, but that takes a good bit of time. Transmutation tablet? Really, it's no worse than UU-matter. It's pretty close, those two, since it was pretty much mostly vanilla blocks. Yeah, you can make some wierd non-vanilla blocks, or fast pistons, but it's use was still limited.
Throw in the condenser, though, all bets were off. I remember seeing one server setup in particular, Four quarries, specifically setup where all cobble went into a box where ACT's pull out furnaces, all gravel gets macerated into Coal, Dirt to a recycler bank churning scrap to a box for scrap boxes with a deployer/obsidian pipe combo, and then of course at the end pretty much the weakest ore-processing I've seen, I think it was just a macerator/induction furnace just piped one into the other...and all of it went right into condensers. It was designed to make the quarry keep up with the condenser. And what did he make? Diamond blocks, for no real use. Same person soon after discovered the macerated blaze-rod trick, and after just had a constant emc setup with that alone.
I think the most concerning thing that EE2 did that people did not like that they probably might be overlooking is what it did to the game. A lot of people ended up looking at everything in matters of EMC. Heck, this is greatly evident on the Tekkit Wiki, as half of the recipes talk about which version is cheaper in EMC, and if it's even worth it to craft. Tech mods are about solving problems with planning and setup, EMC generators and condensers allowed you to skip straight over such problems in the first place. Sorting systems were usually an afterthought to deal with what you couldn't turn into EMC.
Now, of course, not everyone thought like that, but I think we all either remember, or read the horror stories of EMC hoarders on servers basically ruining things for everyone else. I think of EE2 like the Reverse-GregTech of 1.2.5.
And as a little tl:dr, I can sum it up easier, especially for the Free EU idea. In IC2, you don't look at everything in terms of EU, you still consider the resources and upkeep for the items. In EE2, you just look at everything as EMC.