I can understand that a Power Ranger movie styled after the colorful cheesiness of the original show would not likely have a mass appeal in theaters, but when every reboot of an 80's - 90's franchise is made grittier I have to wonder who the target audience even is. The tone of the trailer doesn't resemble the original show in the least so that rules out nostalgia for older fans. On the other hand, the darker tone doesn't seem aimed at children either. If this new tone does appeal to someone, I would have to wonder if they even liked the original show at all.
I completely understand the motivation behind the attempted rerelease of an IP that was previously successful. Many products from music to toys can possess a mass appeal that can cross multiple generations if handled correctly. Batman and The Shadow are extremely similar, yet marketing and the ability to constantly update a character to match the tastes of the era have allowed Batman to become a household name while The Shadow's biggest recent moment in the public spotlight involved a failed movie and toyline in the 90's.
A reboot is just that, an attempt to start over in the hopes of recreating or surpassing the monetary success of the original incarnation of the property. It doesn't matter if the reboot attempt appeals to the older/original audience, just as long as it is profitable (see the Transformers films or the 1960's Batman television show). I just can't figure out who this Power Ranger film is targeting. Many self-professed Power Ranger fans in this thread have stated their own disinterest in this movie and the tone seems much darker than the existing audience for the show that is presently on air. That alone signifies that this film has missed the mark on at least some level I would think.