Not my cup of spiritual tea, but the hate that gets poured out on him defies belief. Christianity is not supposed to be all sackcloth and ashes, right? It called the "good news" for a reason and from what I've seen the centrality of Christ is part of everything Osteen preaches. So I'm not sure what the beef is.
If you’re not sure, you need to research more. This isn’t a hard one to figure out.
But before I pass judgement on Osteen or his church for having large facilities (and not spending that money on the poor), I'd have to have details. For example, it's been my experience in much smaller churches that some donors give just to a particular building fund -- that money can't be used for anything else. It's also been my experience that some donors give money today and pledge future money for tomorrow, and again it's sometimes for a particular project. If that's what this church's building loan was based on, it's hard to judge them for it.
Then there are some cases where a construction company is owned by a member of the church and, therefore, the construction company gives the church a great low cost deal on making a building. I saw that first-hand in a smaller church, but it was a building that had a cost savings in the hundreds of thousands of dollars (not multi-millions). Our small church was criticized for spending a lot of money on it, when it turned out we spent a lot less than was alleged. I don't know if a similar situation happened with Osteen's multi-million dollar building. I do know that I won't criticize it without knowing those kinds of details.
Does anybody know how often Osteen does the prosperity gospel thing? If he does it every week then I have a problem. But if most of his sermons are about trusting Jesus for our salvation, being humble about ourselves, we're saved by grace, but we ought to believe it enough to live like we mean it, with only 1 sermon a year or so about prosperity gospel, then maybe his critics are trying too hard to zero in on something to complain about so they can define the entire ministry on something that's taught rarely. All while the hedonist leftists, not Osteen, are the ones making it harder to be a Christian in the U.S.