I have to agree with this. Even if the lasers can only cover half of Eldin, it's not much of a difference.
Why?
Even with full length lasers, a good player will be able to close the distance. If Falco is trying to camp, he will gradually move back until he reaches the walk off. He will then have to escape to the other side or settle for CQC. When the match starts, you are within one screen of Falco. You're not going to let him get the entire distance of Eldin away from you to start camping. It's seriously not that difficult to get through lasers with a combination of full hop, short hop, air dodge, and even crawling in some characters' cases. So in any case, you will be within or close to within one screen of Falco at all times. Even if you die, you spawn in the middle, and Falco can only get half of Eldin for separation. In no cases should Falco ever be a full Eldin away from any competent player.
Now, if the lasers are capped to only one screen distance, what changes? Only the fact that Falco has to stay within one screen when camping. If the Falco is any good at all at camping, he can easily stay within one screen and still camp you until the walk off. Now look at the above scenario that I just described, in which a good player should always be within one screen anyway. This situation remains unchanged for any competent level of play. Your going to be fighting within one screen whether the lasers are capped or not. Unless you are some sort of sloth, Falco should never be more than half of Eldin away from you. If he does get that far, it's completely your fault and not the stages. You either got heavily predicted, or were trying to camp yourself.
The moral of this story is that capping Falco's lasers will do little to make Eldin viable. People already camp effectively on small stages with way less room (the fact that we even enforce a time limit is testament to this). Any worthy player will maintain a distance comparable to any small stage despite Eldin's size. The size makes no difference in the big picture. The only problematic features of Eldin are it's walk offs and hazards.