“I think most people in the cosmology and astrophysics community believe it's a problem because they've been told that for a long time.” This. Quantum theory d

“I think most people in the cosmology and astrophysics community believe it's a problem because they've been told that for a long time.” This. Quantum theory does not necessarily predict big cosmological constant. All big terms can be cancelled / regularized by some modification of the theory that keeps the results intact. The only problem here is that there is no agreement in how to properly quantize fields and some people think zero point fluctuations are real and necessary to explain some phenomena. However others point out there isn't single rock-solid example of such a need. Not even Casimir effect needs vacuum fluctuations to be explained. But these facts didn't penetrate into mainstream cosmology yet.