JakaB,
Like it or not, the golfing world has embraced fast greens.
Now you can define fast greens differently, or within a range, but, the golfing world has come to expect fast greens.
With that in mind, you can't keep greens consistently fast without protecting them against Mother Nature.
Fans are part of that support system.
Would I prefer that they not exist ? Certainly, but, when they allow a golf course to provide consistently fast greens under difficult weather conditions, you have to accept the bad with the good.
They've become a necessary evil, but, one that's tolerable in light of their effectiveness.
I have noticed, at a club with one fan, that that green is firmer and faster than the others.