I have to laugh when I read some D&D forums and see people who think that GM's owe the players anything more than a good game.
According to Gary Gygax in the books and elsewhere, the DM "is" the game. The players are squirrels trying to get a nut, so to speak.
I look at the roles this way. The DM does what he or she has to do to make a game interesting, playable, challenging, and rewarding. There are tools that are available to the GM in making this happen such as rolling dice. That does not mean that a GM is limited to only rolling dice to make a determination. For any number of reasons, a GM might roll a dice then decide that another result should be the outcome instead that doesn't take dice results into consideration at all.
DM's are, after all, human and are susceptible to the dreaded "Brain Fart" in which something escaped their consideration until "too late" or in the middle of something else. It's entirely in their ability to change their mind, mid stroke.
Some have expressed the idea that if the DM doesn't roll the dice in the open, or if they fake roll a dice or change their mind from a dice result to a chosen result, that somehow the DM is "cheating".
It is my opinion that the only way a DM could cheat is if he or she has an active PC adventuring with the party at the same time and is using his/her GM knowledge to give his/her PC unfair advantages.
I'm not a proponent of DM's sending "full action" PC's into an adventure with a party because it's too east to let such a slip happen. To send an NPC with a party to be a source of information for the party is one thing, to actively play a PC is totally another.
Beyond that, There's not much a DM can do that could really be considered "cheating". If a GM isn't using foils and ruses and keeping players un-aware of their game decisions on the fly then the DM isn't really doing their job. If the players don't understand those things for what they are, they need to get a clue.
As described earlier, A GM/DM has a lot of responsibilities as it is. Of those responsibilities, making sure players hands are held or that players get special treatment or consideration which might take away from the overall game aren't part of those responsibilities.
A Player's job is to use creativity, resourcefulness imagination and the items they have and information they collect as they go along and take on the challenges of any game that comes their way. Odds will be against them, rewards may be not what were expected and opponents may just be too much for them. In the end though, it's the way they played that makes the game for them.
Spoiled, whiny, "I don't wanna play if you don't give me what I want" Players need not apply. This is a game for Heroes, not crybabies.
If the DM isn't giving you challenges, excitement or opportunities you want then you might have a gripe. You can find a different game to go play in or become a DM yourself. That's the power you have as a player
Any GM can plan and run a game, if they aren't making it their own own and giving you a good game, all that planning is for nothing because in the end, you will have no players. Adapt or lose out, that's what the DM has to look forward to. All the planning and thinking and drawing is just words on the wind if you can't keep Players interested.