Credo's are 2 + (credos Completed * 2) number of quests per level, this is constantly criticised as a negative to the game by the vast majority of the games community.
Why this is bad:
Everybody considers "Fisherman, Forager and Hunter" to be the starting tier zero credos. However, if you were to complete credos in the following order:
Fisherman, Forager, Mystic, Quarryman, Miner, Cave Hermit, Hunter
By the time you get to Hunter you will be completing 16 quests per level for a tier zero credo which is absurd.
This used to be circumvented by the "kill yourself to reset your quests to 2 per credo after completing each credo", however all that mechanic did was highlight how big of a problem the credo quest requirements are and then this was removed.
Since the ideal goal (to my understanding of what the developers have said publically) they would prefer people to have one character instead of 10 characters for each niche area of the game. The biggest problem of the game stopping players from being able to success in Haven & Hearth on one character is the Credo quest requirements.
Proposed Solution:
There are several ideas that could possibly solve or lessen the bitter pill that is credo quest requirements however personally i feel the best approach would be to assign tiers to Credos and have a locked quest count per tier to standardise their difficulties. For instance; how they are displayed in the image on the wiki here:
http://ringofbrodgar.com/wiki/Credos
I'm not neccessarily saying that the "tiers" in this graph are correct placements, but doing it this way would ensure that whatever order you do quests in you get a standardised difficulty level in terms of numbers of quests to complete:
Tier Zero (Fisher,Forager,Hunter): 2 quests per level, 10 total.
Tier One (Quarryman, Farmer, Lumberjack): 4 quests per level: 20 total.
etc etc.
This method would ensure a static difficulty curve to credo requirements, at any point in time and in any combination you choose to complete them in, Nomad would always have 8 quests per level, or Mystic would have 6 per lever. etc etc.
I would still keep the "abandon quest" options with this method as its a nice choice to be able to reroll by dropping in progress slightly as that also solves the problem of some credo quests being hardlocked by player development, for instance quarry man having a quest for bloodstone requires the player has a minehole to atleast cave level 2, they can just reroll those out and continue. This would also make some of the less appealing credos more attainable to people.