It's nor the laner, nor the jungler decision which lane should be ganked. It's the game that decide it.
A jungler job is to read the game and be where he is needed, when he is needed as much as he can. He doesn't get to choose where and when the opportunities happens.
As a laner, you may be losing your lane because you fucked up or the enemy was taking advantage of a poor matchup for you or maybe even both of those, but the reason why ultimately doesn't matter, what matters is that if you are losing your lane, it's now both the laner job and the jungler job to make sure a gank happens.
The laner(s) needs to be healthy, ready and try as best he/she/they can to setup a gank... set up an opportunity, the jungler need to be conscious of what is happening and be there when that opportunity arise.
You can't win every lane. Everyone fuck up once in a while and if the enemy use that fuck up, you end up in a losing position and sometimes the only way out is from a gank by your jungler or another lane.
Because once the snowball started, it's a vicious circle that can only be broken by a teammate or if the enemy doesn't do anything with that snowball.
If you don't want to read a story, skip the rest of my post.
For example, in my last game, the other team did the complete opposite of what they had to do and made everything worse for them.
The enemy jungler (Lee Sin) who had the first blood and only kill at 4 minutes in the game came bot to help his bot lane (Kalista + Braum) because they were being bullied by me (Nami) and my ADC (Lucian). Nami completely counter Braum and I abused it by making them pay for each CS they were trying to secure. My Lucian was really good and was following up on my trades. What happened? The Jungler came when the enemy bot lane was half health and we were full with a ward covering the river. The result? Triple kill + double buff for Lucian because their bot lane didn't set up the gank properly (Being half health and Braum jumping to a minion, leaving Kalista too far to engage, and placing himself in a 1v2 until Kalista could catch up), didn't create any opportunity (By baiting us, clearing our ward or engaging as the jungler walk thru our ward instead of engaging too soon) and the jungler came even though he didn't have an opportunity to capitalize on (We were well covered, in a position of vast superiority against his bot lane and it was a very dangerous match up to commit against). To make matter worse he tried to salvage after his bot lane got murdered instead of disengaging, making a snowball lane into a snowball game. 20 minutes later we killed their Nexus at a score of 28 to 7 with a 10-1-5 Lucian and 1-0-17 Nami. Lucian and I didn't waste our snowball. At 13 minutes, we killed the T1 bot tower and brought our snowball to every other lanes and at that point, the window of opportunities was gone for the enemy team. They could only hope for a throw that never came.