i'll say it once before in another forum, i'll say it again.....Hero Mode is an excuse of a mode to say "see this incredibly easy game? well we added a challenge to get through it".
You know what would really be impressive? If ALBW was challenging "WITHOUT" Hero Mode. where you actually value heart pieces just playing the normal mode.
A Link Between Worlds isn't "incredibly easy". If you want to play Zelda games with that status, go play the GameCube ones. ALBW isn't downright hard, but really, outside of Zelda II, what Zelda game is? The answer is none. Some are more challenging than others, but Zelda's always been a series that strikes a balance between not too hard & not too easy (with the exceptions of Zelda II & the GCN games). People just frequently fail to realize that they were less experienced with not just the Zelda series, but games in general as kids (not to mention they didn't have fully-developed brains yet), and on the flip side, that they've become much better as gamers over time and DO have fully-developed brains now.
Games are always going to seem harder as a kid and easier as an adult -- that's just reality. Granted, a lot of NES games were absurdly hard (largely due to 8-bit limitations), and a lot of modern games are incredibly easy, since most 3rd party devs just luuuuv appealing to the lowest common denominator, but Zelda's a special case in that the majority of its games have a pretty similar challenge level. I think it could potentially be argued that ALttP is harder than ALBW, but that's mainly due to the lower frame rate & rigid-in-comparison control scheme, which is artificial challenge. ALttP's puzzle-solving doesn't even touch ALBW's, though.