I think the ideal attitude (for real life) would be one in which an individual could speculate, trust, and distrust. To
simply have love for everything would not be ideal, because we are in a world too complicated and nuanced for that. For example, it is good that we get sick and avoid food that would kill us if we ate it. If we are in the presence of a loud noise, it is best to cover our ears. If a virus infects us, we find ways to eliminate it. Propaganda-wielding despots are opposed. We protect ourselves.
Winston is right to resist, because the torture and re-programming are harming him physically and teaching him to accept lies about the world. In a perfect world (too perfect perhaps), it would, in theory be fine for everyone to completely love each other, no matter what. But I see no reason to believe that Big Brother (a rather prominent member of Winston's world) actually loves anyone or anything--unless abuse, torture, and distortions of reality are believed to be forms of love. By surrendering to Big Brother, Winston has not helped to bring about a world of universal love. He has, instead, fallen victim to a great debasement of the word "love." I think it's pretty obvious that torture, abuse, and the destruction of individuality are terrible precedents for any march towards a "better" or "more loving" world. An "ideal" society could do much better than that.
I have heard of a word called "agape," which refers to the sort of love aspirer seems to be talking about. I think this sort of love is wonderful and important, and that everyone should investigate it. But I think it would be foolish for us to give up our more personal, more individual, more-richly-filled-by-experience forms of love for our friends, mates, and families. A
pre-disposition to love all others is a great idea, however, and I'm not really opposed to it. But that is different than the horrible reflex/habit that has been forced on Winston.
I think it is useful to think of people like Ghandi and Martin Luther King, and their response to oppressive systems. They resisted and interfered with the efficiency and acceptance of the oppressing entities. They did not surrender. And I think they understood the love for others that you have been talking about. Winston was right to resist Big Brother because it is the single greatest impediment to love and respect of individuals in his world.
In a church or temple (or in our home, etc.) we might gain much by exploring the abstract ideas of universal oneness, and universal love. But, like many ideals, these could be abused by those who wish to deceive us and and control us. It seems to me that Big Brother is teaching Winston that an entity committed to violence against him should be loved. This love is made more important to him than his love for anyone or anything else. It follows that Winston would then believe that violence and torture were acceptable means for bringing more love into the world. If one is ready to believe that torture, pain, and disrespect for individuals can be an acceptable foundation for love, then I think one will have been prepared to commit (or accept) any crime against others. The word "love" will have come to have a contradictory ("doublethink") quality. Violence/harm to an individual becomes joined with "love" for the individual. It is, really, a destruction of love. The
word "love" would have simply been re-defined by those with superior power.
So, no, I don't think Winston has achieved an ideal attitude--although the operators of the torture devices will, by necessity believe that they and Winston have achieved an ideal state.
By the way, I'm not sure why someone would come to Big Brother's defense here (maybe just a playful thought-experiment?

), but I think a VERY generous spirit should be careful not to invest itself
too much in the "entrancing" writings/techniques of some self-help "experts/assistants." When the pressure builds, it can be tempting to find ultimate solace in "no-mind" and "living in the moment," but these states, when carried into daily life, can leave us quite vulnerable to outside suggestion. The torture carried out by Big Brother is a very obvious form of abuse/mind control, but
sometimes religions, cults, governments, advertisers, gurus, door-to-door salesmen, website designers, etc. can be much more subtle and gentle in their deceit--even "friendly." And, I suppose, for some of them, their own commitment to an "ideal" might leave them blind to the detrimental effects they might happen to have on others in the real world. Again, I think "no-mind" and "living in the moment" can be useful strategies, but they should not be the only ones available to us.
Now, maybe more than ever, in a world containing more and more "virtuality," I think it is important for us to retain control over our thoughts and judgments, and not get carried away by out-of-place appeals to love or fear. We might be presented with some safe-seeming slippery slopes, but an all-out commitment to abstract ideals can damage our footing quickly in the presence of well-crafted come-ons.