Infinites are somewhat better in Smash Bros. than other fighting games because you can at least DI to disrupt their attempt. While not ideal, I'll take 0-death combos over no combos at all.
I agree with this.
Additionally, unlike other fighting games, Smash Bros has
stocks. In other fighting games, an infinite combo usually means that you just
lost, because those games only usually have a single healthbar and playable character (MvC2 & 3 are two exceptions). Though in Smash, this only translates to losing a single stock. Which, of course, it is still bad. But that doesn't mean that you immediately lost the match, unless you are on your last stock. And unlike MvC2 & 3 and other fighting games, you don't lose
options when you lose a stock. You can play just as well with 4 stocks as you can with only a single stock.
Infinite combos are fine, as long as there is an attached
risk and
difficulty to the infinite combo. For example, El Fuerte's heavy punch links in Street Fighter 4:
https://www.youtube.com/watch?v=bmPO2EpUDj0
While not a true infinite, it can pretty much be treated as one. It requires no Ultra, or Super Meter meter to do. And it even does more damage than all of the Ultras/Supers in the game. But because of how
difficult it is to pull off, you almost never see anybody pull this off. If an infinite is anything like this, then it is fine. Stuff that would fall into this category would be like Ice Climber's chain grabs. Only a few people are able to effectively, and
consistently pull it off. So it is fine for such players to be rewarded for their skill. Plus, it is rather risky, as Ice Climbers have a huge weakness when it comes to losing Nana; making the character far weaker.
Other infinite combos can be bad.
Jab Locking is one such example, because it takes
little skill and risk in order to be able to pull off consistently and effectively. These types of infinites are usually what breaks games, and should be fixed and/or looked into. Most normal 0 -> Death combos are fine though, because those take a fair amount of skill to pull off due to the opponent being able to DI out of certain situations. Plus other factors, such as the amount of damage the opponent currently has (which affects you being able to combo them or not), as well as player-error and stage selection.