During our marriage, I've gone away several times without my husband, but never without my son.
Summer is DH's busy time at work; it's tough for him to take off. However, his parents used to own a vacation home in the Poconos. I went there many times with my son and niece or his parents while he was at home working.
Likewise, my family rents places at the shore in the summer months and invites us down. My husband would never begrudge DS and me the opportunity to join them and enjoy our summer even though he can't. In fact, guess where I'm headed next month?
Personally, though, I do not feel right about taking too much of the family's resources (read: our money) to go to WDW or anywhere on a plane without him. I mean, driving up to the country or down the shore is one thing, but I wouldn't take a big trip unless he came with me and DS.
That said, I don't think it's wrong for other couples/families to do it. I think everyone has to live their lives the way that works out best for them.
For me, I'm not going away longer than a weekend without my baby, and I'm not flying anywhere without my hubby. But I don't think every woman should feel this way.