What people don't realize is all the disagreement is the exact reason I realized alt-coins like Litecoin had a role to play.

When Litecoin (and other alts) were announced I paid them little attention. I just didn't see how they provided significant value enough to be adopted by the community on par with Bitcoin. (I believe Erik Voorhees still has this opinion.)

When the disagreement over Bitcoin Foundation broke out I realized with startling clarity there could be irreconcilable opinions between people, no matter how much debate ensued. I saw this could apply to more disputes than just the foundation, and might even threaten Bitcoin (with tempers, hard forks etc.) as stakes grew and more opinions came on board. I felt there was growing risk in corralling increasingly divergent opinions under one tent, and expecting harmony. Indeed this was long before the block size issue blew up in the community. A single coin I felt invited disaster because while threats from the outside might be defensible, a diverse group unable to counter infighting (and possibly corruption) could fall from within.

That was the important feature I realized alt-coins had which Bitcoin didn't. They provided an alternative. That was the thing Bitcoin could never provide by itself. After I realized this I found other ways alt-coins strengthened cryptocurrency overall (like providing technical/economic backup, easing pressure on block chain scalability, experimentation, etc.).

While I missed the significant value of alt-coins at first, I later realized they could be indispensable for trying to gain cryptocurrency success overall.

What people against Litecoin (or Mt.Gox adding it) I think don't realize is it's probably inevitable already Litecoin will see widespread adoption. Whether or not Mt.Gox adds it doesn't change the large number of people already holding it, which is where coins get traction/value in the first place. There are 18,810,954 litecoins in people's hands now. That's slightly more than the number of bitcoins currently. Litecoin is already being exchanged and has a growing user base, just like Bitcoin.

Last, for those worried about an unending string of new coins, don't. You can't stop that happening anyway, and you may even find (later as I did) real benefit to this. The reason new coins can't easily destroy older established ones is exactly because older coins are older and established. Any coin's code can be duplicated, so coins competing on that level only are not differentiated. What can't be duplicated easily is the willingness of a large user base to use a coin. For every coin that attempts to gain this, but offers no real value, i.e. reason to be adopted, the coin's value is never any more than how quickly the features it has can be cloned (i.e. probably zero).

If you don't believe more than one coin can co-exist and be valued by the market properly (and differently) you're not paying attention. That is already the situation we have now.