For me, no. I have stayed at the Double Tree many times when I'm come in at night and just need some place cheap before my onsite stay starts. I really like the DT and the location is great. You can walk to the parks from there but to me a Universal trip has to include staying at one of their hotels.
A big part of the experience for my family are the Universal hotels. We have stayed at all three and fotl, having an easy walk to the parks and just the feel of being onsite is a requirement for us to go to Universal. If my family had to choose between going but staying offsite and not going, we would choose not going. Of course that is just us but it tells you how much the onsite hotels are what we consider a part of a Universal vacation. Many disagree with that.