Were the Crusades Bad?

Were the Crusades bad? No. In fact, they were endorsed by the Church in 1274: 

"Zeal for the faith, fervent devotion and compassionate love ought to rouse the hearts of the faithful, so that all who glory in the name of Christian grieved to the heart by the insult to their redeemer, should rise vigorously and openly in defence of the holy Land and support for God’s cause. Who, filled with the light of the true faith and thinking over with filial affection the marvellous favours conferred on the human race by our saviour in the holy Land, would not burn with devotion and charity, and sorrow deeply with that holy Land, portion of the Lord’s inheritance ? Whose heart will not soften with compassion for her, from so many proofs of love given in that land by our creator? Alas! the very land in which the Lord deigned to work our salvation and which, in order to redeem humanity by payment of his death, he has consecrated by his own blood, has been boldly attacked and occupied over a long period by the impious enemies of the christian name, the blasphemous and faithless Saracens [Mohammedans]. They not only rashly retain their conquest, but lay it waste without fear. They slaughter savagely the christian people there to the greater offence of the creator, to the outrage and sorrow of all who profess the catholic faith. “Where is the God of the Christians ?” is the Saracens‘ constant reproach, as they taunt them. Such scandals, which neither mind can fully conceive nor tongue tell, inflamed our heart and roused our courage so that we who from experience overseas have not only heard of those events but have looked with our eyes and touched with our hands, might rise to avenge, as far as we can, the insult to the crucified one. Our help will come from those afire with zeal of faith and devotion. Because the liberation of the holy Land should concern all who profess the catholic faith, we convoked a council, so that after consultation with prelates, kings, princes and other prudent men, we might decide and ordain in Christ the means for liberating the holy Land...We held frequent consultations with them [the Greeks] about help for the holy Land, and they, zealous to avenge the insult to the Saviour, thought out the best ways to succour the said Land and gave, as was their duty, advice and insight [Con. I., II Cll. Lyon, from Dec. Ec. Concls., Norman P. Tanner]."

There were certain deviations such as the 4th "Crusade," but I do not consider the deviation to be a crusade. Crusade was a military expedition to the Holy Land which was under the cross, but this was not, and therefore, it was a pseudo-crusade.