While I understand your general point, I find it highly doubtful that 75% of _Postgres_ users are on Windows. I strongly suspect that they are in the minority by a wide margin.
But if Postgres wants to expand its user base a good graphical client for Windows would be a big help. I think that it is a major reason MySQL is way more popular.
I'm pretty sure the major reason MySQL is "more popular" has more to do with its ubiquitous install base on low-end web hosting providers than the (non-)existence of Windows-based GUI clients — particularly given that PgAdmin III has been around for at least 10 years, and cross-platform the whole time.
I agree with the idea that postgres should have better clients for Windows. It's the major reason I never used it for anything serious. Even commercial tools lack behind.
What I mostly miss is a good tool focused on writing SQL like Management Studio from MS SQL Server. Something that allows me to easily open complex large scripts in a full editor, execute parts or all of it easily and get results back. Not much gui, not many wizards, but a good experience. Most tools I find for pg are either full console or full guis with too much focus on wizards. It's like the people using it are uncomfortable with SQL for some reason.
But having followed pg for 15 years or so, I don't think they want or need to be the most popular database. They just want to be a damn good database server, and they are.
I don't find it that hard to believe. All companies I ever saw using postgres are using windows for development.
Note that I'm not from the US, I'm from Brazil. Here windows pretty much dominates the landscape.
But this is also important: while the US is currently quite apple-centric, most countries are not. And although the US concentrates a lot of tech companies, it's still only 4% of the world.
I'm not stating that these stats are the ultimate sources of truth. But those are good references. If you were to measure the reality in most countries, I doubt those numbers would swap places.
In Brazil I see lots of devs using Macs too. It's just not the majority of them.
Depends. Last summer I strolled into one meeting, where a typical enterprise project was discussed (Windows servers, MS SQL, Sharepoint, whole enchilada) and almost fall from my legs, because all the prime contractor people were using Macs.