I've repeatedly heard low player usage of the 1939 start date as justification for the decision to not include other start dates. While I certainly am not a part of Paradox's long-term strategy discussions, I sincerely hope they don't take that sentiment too seriously because it's simply a bad way to prove the point. Allow me to elaborate.
1. What is the appeal of the 1936 start date vs. the 1939 start date?
Starting earlier allows players much more control over prewar buildup, how one progresses through the focus tree, and in general allows the player more latitude to shape the country they're playing as, including along ahistorical paths. More time allows for more familiarity with the OOB, the industrial capabilities of one's country, and better long-term planning. There are other reasons for the 1936 start date being the most popular, but those are largely variations on the player options element.
2. What would be the appeal of start dates earlier than 1936?
Basically the appeal of 1936, but more so. There are obvious drawbacks to earlier start dates, such as monstrous focus trees, potentially long periods of doing nothing, the overhaul of various realms of mechanics to make such a start date viable, etc. However, such things could be done and an earlier start date has been discussed ad nauseam in the past weeks, so the crux of this thread is more that the reluctance to play 1939 does not translate into reluctance to playing 1935, 1934, or 1933 start dates. The advantages of 1936, the most popular start date, would be more greatly felt in 1935 and so on. Sure there's some balance involved, but again the point of this thread is not to discuss the viability of those start dates.
3. What would be the appeal of start dates later than 1939?
The appeal of later start dates, which I played frequently in earlier HOI games (usually the 1943 and 1944 dates) is twofold.
1. Historical play. We all know there is a sharp divide between people who want more focused historical play, and people who want tons of alternate history options. Personally I think both have their place, and later start dates allow for historical situations, tech progression, troop disposition, etc. Later starts allow you to play the Battle of Kursk, blunt the Axis offensive at the Battle of the Bulge, or pull a stunning come-from-behind victory as Japan playing against its historical disadvantaged position. Games played from 1936 or even 1939 almost never relate to the historical situation at a corresponding date, so later start dates allow this to happen to some extent.
2. Challenge. Right now the game is an absolute breeze unless one arbitrarily buffs the AI. It's far too easy to avoid Germany's historical mistakes (indeed one needs to try to make mistakes to replicate the historical situation). Similarly, playing as the Soviets I've not once had to move my industry east. Later start dates allow a player to put him or herself in the shoes of the Soviets clinging to Stalingrad in 1942, or the Germans desperately trying to regain the initiative at Kursk. I can't express how much I enjoyed earlier HOI games' late starts simply because of the challenge they posed, and my most memorable games started after 1939.
4. Why is 1939 seldom used as a starting point?
It has none of the advantages of earlier starts (ahistorical options, buildup to the war), and none of the advantages of the later starts (challenge isn't really there unless you're Poland or France, and the historical situation is uncomplicated). It's the jack of no trades. I personally never used it in previous HOI games, and I don't recall using it once in HOI4.
5. Why is the low usage of 1939 not a good data point to prove that players don't want more start dates?
See the previous points. Since it has none of the appeal that both earlier and later starts would have, reluctance to use 1939 doesn't translate into reluctance to use other potential start dates. It's all detriment but no benefit (unless one is interested in playing Poland against impossible odds). As such, it doesn't show that people don't want start dates other than 1936, all it shows is that people don't want to play a 1939 start date.
What should Paradox do about this? Nothing, for now. The game has much larger issues that need to be resolved.
However, down the line there should be some serious consideration of adding later starts. Some mods are currently making an admirable effort but the fact is that for compatibility and other reasons, Paradox is the best equipped to at least provide the baseline for new start dates. I would gladly buy a DLC that consists of new start dates.
