Expendable Camos are worth credits. Even if you have no interest in using them for aesthetics they still hold direct in-game usefulness through giving buying power for Ships, Upgrades, Commander XP (dismissing Commanders), and Signals purchased from the Armory (and more if getting specific). They sell for 45,000 Credits each so the 15 you can earn total to 675,000 credits if sold. As the Camos are all in the freely obtainable section of the dockyard, credits as a reward is not that strange.
As for "value" in a conceptual sense, everything holds as much value as a player gives it. Commemorative Flags and Patches give no gameplay benefits but they are fun to collect. Camos are undergoing a bit of an identity crisis right now as they had a solid concept that was in place for many years which has changed recently, but they still hold value aesthetically, collection-wise, and/or credits.
As for Monetization being a thing... it is a thing. We are a business that needs money to operate and opening new studios is a sizable investment into our company and long-term product availability. I am not on the monetization team, but all of our items and offerings are weighted in terms of value so that what we offer is believed to be appropriate for the effort. The earlier stages are easier, so one of the milestone rewards is 5 Expendable Camos. Later on, it's 10 Expendable Camos as the effort required to attain them is harder. We are aware of player concerns regarding Camos, but right now we continue to feel they have real and immediate value and do offer Expendable Camos in Events, Missions, and Containers.
It's hard to strike a balance when choosing Ease vs Effort. Evaluating that isn't my department, but Combat Missions are typically weighted on "Expected Number of Battles to complete". The missions for the Puerto Rico do get harder in the later stages, which is a norm for our Dockyard model.
You are correct that allowing the Missions to exist for a longer period of time would mean more content for those that haven't finished them, but we will have new events and content to complete that is slated for that timeframe. We work rather hard to make sure there are a variety of things to do through events, missions, ship releases, and more.
This is correct. It's an unfortunate reality of the business.
Each ship has a 2 year development cycle in terms of pipeline and labor, combat missions require planning and implementation with code support, and the various other factors that exist which make doing something well into a time and labor intensive task. Our model focuses very heavily on producing content for players to interact with instead of just assuming the base game is all that is required. Our game is excellent, but many players which enjoy Free-to-Play games prefer the additional motivation of a goal or external reason to assist in their engagement. The need for extra impetus is perfectly natural which is why it's part of what we do day in and day out.
You also mention "They don't want you to log in for a marathon at the start of the patch, then drop your active time a bunch until the next big thing hits. It causes huge spikes at the beginning of a patch and then an equally large drop in players for the rest of that patch's cycle." which is absolutely true in the case of hardcore players. Some players will be driven to complete things immediately, regardless of the task size, and it can fuel burnout from completionists.