Well, you could try, you know, EXPLAINING YOUR ****ING STATEMENTS.
I dunno, just a thought there.
Alright, sorry if I sounded rude here.
Now, if you were talking about singles play, then maybe I wouldn't disagree with you that much. And also if you were talking about a direct confrontation between Fox and Falcon, then you would be absolutely right. But remember that we are talking about doubles/team matches.
Just how realistic is using shine spikes in team matches with Fox? How does it compare with Falcon's options? It really boils down to two things: the character you gimp and the recovery you have.
Shine spike is mostly effective vs Fox, Falcon, Ness, Kirby and Puff (assuming the last two characters are found in a situation below the edge which is extremely rare at low% unless it's due to a serious error). Looking at Falcon's options, his aerials are great for gimping characters with weak recoveries. His main tool of choice, dair, is not only better at killing the characters mentioned above (except maybe Falcon at 0%) but can also hit others that Fox's shine spike can't realistically hit (Pikachu, Donkey Kong). Falcon also doesn't need to/doesn't need to go as far offstage to gimp with dair.
And in the case that you do shine spike someone, you have to realize that you will most likely be offstage. This may be yet another point you'll want to debate on, but Fox's recovery is significantly worse than Falcon's for team matches. Fox has too much startup on his up-b and it usually gives too much time for the other opponent to deny his coming back to the stage. While Falcon not only has far less startup he can also space his recovery to grab the edge far more safely and efficiently than Fox can. If given the opportunity he can also attempt to up-b grab an opponent who just failed an edgeguard.
I might sound like I went out of subject here. But, in team matches, a character's potential at gimping is EXTREMELY reliant on how good his recovery his. Gimps don't mean much if you'll get gimped yourself.
That being said, with a good team mate, both Fox's and Falcon's recovery weakness can be nullified if the partner protects the edge for you. However startup and safety are still very important factors.