Jungle main here.
I'll be honest, it's a trust issue.
you could very well be doing everything right and still not get ganks, it's not that you are not worthy of it but there are alot of factors.
Like who you are Versing. Depending on who im ganking, maybe it's someone that has way more mobility than me and can easily get away with or without flash like say
for example, if i'm playing someone like
I know that unless you got some hard CC i have to rely to make the gank successful on it's almost pointless. I mean the most I could do is maybe get then to run away from you to give you a breath of air and thats it, the problem with that is It might be a better worth of time to gank bot lane or mid depending on who we DON'T want to get fed, like a
mid or maybe a 
Other times it could be because of who I'm playing as and i'm not confident in myself early on. Like say
I may AFK farm till level 6 because I feel worthless otherwise. Especially if the enemy has alot of tanks or champs with survivability, and I need to wait till they have low HP that I can capitalise on.
Sometimes it's just too hard or impossible to gank, too many wards?
mid is suicide to gank on,
top once he hits 6 can be hard as shit to gank.
then it maybe because they are too fed, and I know most think it would make logical sense to try to shut down the fed champ, but sometimes they can IN FACT 1v2 and kill both you and your jungler, making it even worse, then it becomes a risk to come help even though maybe I should have been there earlier.
There's A Lot of decision making as a jungler, and though some choices look painfully obvious to you, it may not be so to us. Sometimes the support misses a grab or stun, sometimes the top lane loses lane, sometimes the jungler made bad decisions that game.
Hope this answers your question.