I think most of us Cowboy fans need to be more reasonable about why other teams dislike the Cowboys and Irvin in particular. So I'll keep this short, here goes:
We all know the Cowboys history but short recap necessary. We became a team in about 1960. By around 69 we improved enough to face the Packers in the SB forever more called the "Ice Ball" which we lost but won lots of fans for our efforts. We made it to 4 SBs in the 70s winning 2 (Denver & Miami) but losing twice to the Steelers. We had great players and a great organization which almost instantly attracted media coverage and generated a significant group of fans--not only in Texas--but across the country. We were down in the 80s but the lure of our former great players & Landry & Schramm ingenuity ensured we remained a very visible team.
In the 90s we came back again to win 3 SBs in 4 years (never been done before) with several great players--most notable the Triplets--and a good organization. Unfortunately that team--the team of the 90s--also had off field problems with Irvin the most well known (but other players also contributed) to seriously tarnishing the Cowboy image; Jerry Jones firing of Landry and his brashness didn't help. Many fans became ashamed of the Cowboys (even while proud of our SB wins) but fans of other teams lost respect for us & that continues to this day. Now I'm not saying we weren't hated before the 90s (see the Skins/Giants/Eagles) if you doubt their level of hatred but some of the casual fans stopped rooting for the Cowboys as their 2nd favorite team.
Now keep in mind that we've been to 8 SBs and won 5 of them. Many other NFL teams have either never made it to the big game or lost when they got there so their Lombardi Trophy count is "0". They also see the media circus surrounding the Cowboys--even in our losing ways or lack of playoff wins since the late 90s--and frankly don't think it's fair or are jealous. That's entirely understandable and very human.
They also vehemently resent the Cowboys being called America's team (Packer fans still insist they America's team, Pats fans feel the same and now so do the Colts. Fans of other teams also refuse to understand and/or accept/acknowledge the Cowboy drawing power in television ratings, resent the large Cowboy fan presence in their own stadiums when we play there, hate many of our present stars for any variety of reasons including constantly replaying 90 off-field activities & even deny Cowboy fans are real fans by claiming fans can't even identify some of their own starters, only root for the Cowboys when the team does well, etc. Most hate Romo to an unbelievable extent given he's a QB whose only played 10-11 games and feel he got too much hype in 06 (wouldn't have got if he played for elsewhere). They desperately want him to fail in 07 cause if he succeeds, the Cowboys could be a legit SB contender AGAIN & they'd have to put up with our winning ways again why their own teams don't suceed to the same level. Few teams want to compare their own success rate against the Cowboys could few could survive that comparison.
As for our East opponents (all of whom have much older histories then we), our existence (and huge following) is a constant reminder we've suceeded wildly beyond any expectation where they've failed. We've won 5 SBs to the Skins 3, Giants 2 & Eagles 0 and of course we do consistently point that out to them. Most people don't consider Cowboy fans to be the quiet retiring type & many fans do tend to rub it in their faces. So live with the hatred the Cowboys receive, not only from East rivals (we also hate them) but from most other teams.
Now I love the Cowboys and the high television ratings they engender cause I get to see a lot more of their games here in Tampa. I expect to see at least 10 Cowboy games this season. While most will be evening games as well as the Thanksgiving game, the Cowboys will also be playing several 2nd games on Sunday and you can bet (certainly the 2nd game of the season which will be in Miami) several will also be national games. Can't wait. BTW: I also love Michael as most Cowboy fans do and accept his fralities and work to overcome them, love being called America's team (cause we are despite contradictory views) & love to hear about all those fans/media attending our TC in comparison to other teams. Also despite the claim by so many other fans of other teams who complain they know Cowboy fans who can't even name 3 Cowboy starters, I can name every Cowboy starter and their backups (although could be shaky on bottom level of the roster. I do admit to not knowing names of all our coaches after Wade, Stewart, Garrett, Wilson, Dat, Sparno (sp?), Bowles, Wade's son, Pasquilllo (sp?) & Peete unless I check out DC.com. Guess that makes me a fair weather fan. Ha.
Point of this all article is we all love our fans and should simply accept that many others do not for a variety of reasons which we think unfair but who cares. Just like who cares what they think of Michael Irvin cause we all know in our hearts every NFL team would have loved to have him playing for them, warts and all. Ask McNabb if he loved throwing to Irvin, same for Favre & Eli Manning would probably .... his pants if he could have Irvin over what he's got.