The eldar are a winnable army, construct your list right, use the right tactics for your list and don't have bad luck...you will win...as with any army in the 40k realm.
It's just a shame that it's not viable to take some of the more cooler models in a tourny when your opponent is unk. Might sound silly but when i first started playing i knew nothing about 40k, i bought the codex and my order of priority was the models i liked. (that was back in the 2nd ed) When i play now my lists are so different it's like a separate race...
3 scorps, 5 Sw Hks, 2x5 man Gdn sq, 6 jetbikes, 3 warp spdrs, 1 vyper, 1 farseer, 1 WWkr, 2 exarchs, 3 Dk rprs, 1 Wthlord
that was about 1000pts, no starcannons at all, well rounded force back when that was basically the only units i owned.
Now days it's a lot different:
Farseer, 10 banshees & Wve srpnt, 5 warp spdrs, 8 fire drgns & wve srpnt, 2x5 man gdn sq & str cn, 10 dire avngr, 4 vypers,
1 wthlord, 4 dk rprs, 1 falcon, 4 exarchs in total. about 1500pts, 6 starcannons, a lot of models gathering dust on the shelf as i have about 90% of the units in the codex now.
Broken...maybe a little. It would take very little to fix, but that's another post.