It makes sense. Yoda and Obi-Wan seemed to have way more patience than he did. If he were alive he'd either be fighting the good fight still (which he isn't) or he'd be a shell of his former self; broken and crippled, no longer the Mace Windu of the Jedi order.
I agree the man not being same as he was. Personally I don't care is he alive or dead in any of your games. If it works for you, great.
Alas, he's in the same state as Boba Fett is at the moment. Both alive and dead until Disney Canon confirms one of the two. The difference between the two is there are at least "Legends" of Boba Fett surviving the Sarlacc... There are no Legends of Mace Windu after his fall.
Schrödinger's Windu and Fett. I love it.
All that and I think Mace is an incredibly overrated character that showed just how far the Jedi had gotten from their true purpose. He tried to assassinate Supreme Chancellor Palpatine!
This "showed just how far the Jedi had gotten from their true purpose" is exactly the thing I liked him most.
That said, I am not trying to tell you how to view anything or what to believe. I'm just stating the character is canonically dead until more stories about him post RotS are made. Also that I personally would prefer him to stay dead.
I agree (on the canonical part. I still don't care very much about to which state schrödinger's windu ends up.)
Few thoughs regarding Windu and EotE game. Mace Windu was 15 years older than Kenobi, so he's quite a old if game era is the default. Personally, I think that idea of old disillusioned (maybe alcoholic) Windu, and bottom of his life would be interesting thing in game, but I probably wouldn't use it in default era (approx 0 BBY - 3 ABY if I have understood correctly), because 72+ years old Windu would be quite a geriatric and I couldn't see him very usefull at any way, at least if he has been living with a bottle for 19 years (which in my game he probably would have). But in game which would be set at e.g. 15BBY, might be interesting. Can PCs help him redeem himself, or will he finally give up and fall.
If I'd use Windu in default era game, he would probably be old man in streetcorner telling stories (1) for few credits to buy food/booze. He might redeem himself in death, for example helping PCs, but PCs might not even realize who he is/was. Anyway, he would be in small role, because I want PCs to be the main cast of my games. (Because about half of my GMing life (twenty years with some long gaps), my greatest sin was to make Mary Sueish NPCs to save the day. Nevermore.)
(1) After all, "Windu, a diplomat by nature, believed in the power of words over action." Source: http://web.archive.org/web/20110903003408/http://www.starwars.com/databank/character/macewindu/index.htmlbut after reading the old starwars.com page about Windu, I think that most what I wrote above is obsolete.