To be fair, it is a more complex issue than either "side" of this argument has expressed.
There are variations in construction quality and style from region to region, and within a region. Differences in what the primary reason for venting the attic is, etc..
I think we can pretty much all agree that slapping a powered attic ventilator and some soffit vents in the average home "as built" is going to have some undesirable consequences.
This fact has been well established by basically everybody that has ever made a study of the subject.
We can also agree that it is possible to seal the conditioned space off from the attic well enough to prevent most of the usual list of undesirable consequences of PAV's from being an issue.
I say "most" because, short of replacing all of the offending combustion appliances with sealed combustion 100% outside combustion air models, you cannot used forced attic ventilation in a home that has combustion appliances located in the attic, or that draw their combustion air from the attic.
That bit excludes a good 2/3 or more of the homes in my service area from using PAV's.
So lets say we have established agreement that the average home needs some improvement before going forward with using a PAV, and that except for specific exclusions, it is possible to make enough improvements to allow the use of a PAV without undesirable air leakage from the conditioned space.
Now we have to look at how much those improvements will cost, vs what they will save.
In most cases, most of the improvements will be worthwhile in and of themselves, regardless of how the attic is ventilated, so on average are not really factors in the PAV vs no PAV debate.
So lets take an average all electric home that we have sealed adequately to prevent air movement between the conditioned space and the attic, and has a continuous soffit vent with plenty of free area.
Now we have to decide between a PAV and effective passive ventilation.
Unfortunately there is only very limited information available from the building science community to help with that decision.
If you stitch together the handful of very small scale studies that have been done under relatively ideal conditions on properly sealed instrumented test houses, the data suggests that the energy savings from a PAV will be only little higher than the energy input to operate it.
The sample size of the instrumented house testing that has been done is very small though, so the results are not conclusive.
While I'll admit that there are situations where a PAV is a perfectly acceptable attic ventilation method, for now I'm sticking to my blanket recommendation against them in my part of the country.
To be quite honest, the average quality of construction in my area, even on $million+ homes, is horrible. Little attention is paid to the integrity of the pressure or thermal envelope of the homes.
In most cases it is not even remotely economically feasible to do much more than seal the big leaks enough to stop naturally occurring air movement between the conditioned and unconditioned spaces.
In most of the 2 story homes around here, it would be an expensive effort in near futility, that may require some reconstruction of parts of the house, to try to seal well enough against a mechanically induced pressure difference.
I've mentioned the combustion appliance issue enough already, but I understand that not all parts of the country do stupid crap like put furnaces and water heaters in attics, or duct their combustion air from the attic.
My recommendation, for my area, will continue to be effective passive ventilation, a radiant barrier, sealing the ducts as tight as possible, sealing the big leaks between the conditioned space and the attic, and blowing in more insulation.