There are many reasons for the renewed focus on the moon. Microgravity is only one of them. China making moves to establish a presence there is a big motivator.
Then we have the retirement of the ISS to consider. Most of the ISS will be left to burn up in the atmosphere. Aside from some Chinese and Russian modules which will be boosted back into a stable orbit. The rest of the ISS will not be boosted up. Every day the ISS falls closer to Earth and every so often needs to be boosted into a higher orbit. This is expensive, requiring the shuttling of a great deal of fuel. The sheer size of the ISS has been its downfall in this regard. The lower gravity of the moon means much larger orbital stations can be built there, which will fall much more slowly toward the moons surface and which will need less fuel to be booted back into higher orbits. The new ISS will be in moon orbit and will conduct experiments which cannot be done within the magnetosphere of the Earth. Like finding out how astronauts deal with extended stays in zero-g while exposed to space radiation.
There is also a push to exploit minerals on the moon. There are several locations where rare earth elements are relatively abundant on the moons surface. Currently the bulk of these resources on Earth are controlled by China. This makes the moon a location of strategic national interest. Construction of a mineral processing facility will be advantageous and will provide a location to facilitate exploitation of asteroid materials.
The moon also provides a relatively safe location to act as a quarantine station for astronauts and samples collected from other solar bodies. It is prudent to consider the possibility that hazardous substances may be lurking in many of the samples we will collect and in many of the environments we will explore. You may laugh at the idea of a space virus spreading through the population of the Earth but I do not consider it a comedic possibility. Especially given the prevalence of tholins on orbital bodies. It is a near certainty that we will at some point encounter a substance which is radically dangerous to us.
I doubt the moon will ever be properly colonised due to its proximity to Earth. The moon will have a largely transient population of temporary workers and people who are just passing through. Mars will be colonised out of necessity due to its distance from the Earth. Additionally colonisation insists upon self sufficiency, constant provision of basic supplies is simply not feasible for any habitat BEO. Some advanced supplies will be needed but they will be traded for.
The reason Mars colonisation will be delayed is because no government will support sending settlers out into the vast unknown potentially to meet a horrific death. Again public will is at the forefront here. The first steps beyond earth orbit need to be inspiring and successful. Failure is not an option.
There is one more reason why Mars colonisation will be delayed... We still do not know if life existed on Mars. Once the surface is opened up to private companies the whole planet is going to get contaminated by evidence of life from Earth. We only have one opportunity to answer the question "did life start on Mars".