It's Either The Church Jesus Started-Warts and All - Or It Isn't
The worst "liturgical abuse," IMHO, is knowingly being in schism with the Church Jesus started. It's either the Church Jesus started, warts and all, or it isn't, with all its imperfections brought about by our human condition. If one claims to be Catholic, he or she has given up the "right" to decide what's the best form and style of worship--so long as everything is done in accordance with the Church's liturgical norms. Those who insist that one rite is better than another (even though the Vatican has approved all rites) come perilously close to making the same mistake that the reformers made. They "knew" better than the Magisterium of the Church, essentially putting themselves on a par with the Holy Spirit. I have spent 31 years of my life as a Protestant, believing all manner of heterodoxy and participating in many forms and styles of un-orthodox worship. If I now experience a Mass that is "less than orthodox," or has some degree of liturgical abuse in it, as long as the Eucharist is validly consecrated with proper form and matter, Jesus is there, and I can offer my sacrifice in union with Him to the Father. This the true sacrifice of worship, and it happens regardless of bad homilies, mediocre music, banners from the 70's etc. I am so thankful to be Catholic and have had the opportunity to receive Him in Catholic churches all over the world in which I have worshiped, from Galway, Ireland to Port-Au-Prince, Haiti to Los Angeles, California to Orefield, Pennsylvania.