Pretty much echoing what everyone else has said.
But, let it be known that in my opinion, there is somewhat of a variance when it comes to the term 'spamming'.
When someone who obviously doesn't know what they're doing; EX: Ike player standin/walking around and just using F-smash- then its your responsibility as a player to defeat this dumb *ss tactic.
When someone is strategically using projectiles; like diddy's banans, it may look like spamming to you, but bear in mind that there is an awful lot of thought that goes into it. I used to be a Link mainer in Melee, and I didn't throw a bomb or boomerang, or shoot an arrow without knowing EXACTLY why I was doing it. If I'm not mistaken, Caveman made a living out of this camping/spamming w. his young link.
Believe it or not, it actually takes a lot of skill to EFFECTIVELY camp/spam moves. Requires you to know the timing/distance/feel of each projectile or move, and know when, how, and where to use the projectile in conjunction with where to place yourself relative to your opponent.
Neither one (skillfull camping or wildy spamming) should be banned for the following reason. Wildly spamming should get the person punished in the match, by the opponent. Skillful camping is in and of itself a tactic/skill. The only exception is those techniques used for stalling a match to secure a victory.
These matches may not be fun to watch or play, but when $ is on the line- it isn't about putting on an entertaining match, its about doing what it takes (within the confines of the rules) to win. Tournament rules are pretty good, and stringent enough as it is allowing for fair gameplay. Not to mention the impracticality of the idea of banning spamming/ers, as its impractical to monitor each match; especially at the HUGE tournaments where director to player counts are EXTREMELY slim.
