Why did the Church ditch the Sabbath and the Lord's Feasts?

In my previous post I tackled some issues stemming from the Roman Catholic Church's decision to alter God's calendar. Now I want to look at the Sabbath and the Lord's Feasts in a little more detail.
The Catholic Encyclopedia says this about the Sabbath:

St. Paul enumerates the Sabbath among the Jewish observances which are not obligatory on Christians (Colossians 2:16; Galatians 4:9-10; Romans 14:5). The gentile converts held their religious meetings on Sunday (Acts 20:7; 1 Corinthians 16:2) and with the disappearance of the Jewish Christian churches this day was exclusively observed as the Lord's Day.

This is a terrible abuse of Scripture. Paul is not telling Christians to not celebrate the Sabbath or the Lord's Feasts as celebrated by the Jews. In Colossians 2:16 he is telling the readers not to let anyone pass judgement on anyone else regarding eating or drinking or the keeping of the Festivals. In verse 17, he states that those same festivals are a shadow of things that are coming which seems to indicate that they still have some relevance. And in verse 18 he begins an admonition against following man-made rules and teachings(see previous post on the Magesterium); things like self-mortification(many orders of monks have been big on this) and verse 21 sounds like a direct contradiction of Catholic teachings about avoiding meat on certain days, ect.!
Next, let's look at Galatians 4. But to get the meaning, we need to back up a verse.

8 Formerly, when you did not know God, you were slaves to those who by nature are not gods. 9 But now that you know God—or rather are known by God—how is it that you are turning back to those weak and miserable principles? Do you wish to be enslaved by them all over again? 10 You are observing special days and months and seasons and years! 11 I fear for you, that somehow I have wasted my efforts on you.

Now the Catholic Encyclopedia is saying that this is referring to the Jewish Feasts. But who was this written to? GENTILES!!! Who were the Galatians serving before they believed? Other gods!!! So, what is Paul talking about them "turning back" to? It certainly isn't Jewish Feasts! Do you think that Paul would call Jewish Feasts weak and miserable principles?!? Do not forget that pagan culture had its own "special days and months and seasons and years" I don't think Paul was worried about Gentiles being enslaved to Jewish Feasts "all over again"!
Lastly, there is Romans 14. The entry above cites verse 5, but for some reason they don't go on to the rest of the passage. You all know the first rule of Bible study and interpretation: context, context, context!!! Romans 14:6 says, "He who regards one day as special, does so to the Lord. He who eats meat, eats to the Lord, for he gives thanks to God; and he who abstains, does so to the Lord and gives thanks to God." So it is possible to go ahead and celebrate the Feasts to the Lord, or to not celebrate. But this certainly isn't an injunction to dump them or not celebrate them at all. Later he says in verse 17 that the Kingdom of God is not about eating and drinking but about righteousness. God's Feasts were never about saving anyone (Jew or Gentile); they were a demonstration, a dress rehearsal if you will, of His perfect plan. And they still are.