Dear Jake:  

I have hesitated a little before answering your question. Personally I love the so-called 'New Rite' on two accounts: its dignity and clarity when celebrated as it should, and the fact that it is the chosen rite for general use in the Latin Church. You have to be blind not to see its dignity and power when you witness a Mass celebrated by the Holy Father on any of his trips. 

To answer your question on excommunication: the law of the Church, Canon Law, tells us that 'A bishop who consecrates someone a bishop and the person who receives such a consecration from a bishop without a pontifical mandate incur an automatic (latae senententiae) excommunication reserved to the Apostolic See.' (Canon 1382). That is precisely what Archbishop Lefebvre did. No matter what explanations are made, the fact remains: some men (the ordaining bishop and those ordained) were knowingly and deliberately disobedient and thus placed themselves outside the Church by their very act. There may be problems in the Church (there will always be, as long as Catholics, priests and bishops included, are human), but the way to solve them is not by disobedience to the Holy Father. 

The break away of the SSPX has saddened many in the Church - beginning with the Holy Father himself, and many Bishops clergy and lay-people. The reasons that are usually given to justify their actions have scandalized and mislead many good people, and done great harm to their faith. 

At the bottom of this whole question lies a subjective, and I would say, protestant, idea of the Church, and a false concept of Tradition. They tell us that the means that Christ chose to insure the endurance of his Church and his presence in the Church for all time (the office of Peter) has let him down, and in something as fundamental as the validity of the Mass. Just like the Reformers, they say the Catholic Church has gone astray, that they are privileged with an insight that allows them to single-handedly reestablish the link of fidelity. If the Church wants to be what Christ meant it to be, if the Pope is to do his job right, he has to come around to their position. They are his 'faithful sons' waiting for him (the Prodigal Father?) to return. 

I do not think anybody wants to destroy them; we all hope and pray that they will be reunited with Rome, and contribute their energies to the New Evangelization. 

God bless,