I still recall, when the first "Mantis are dead" announcement came out...
Some context, for the new people: I really hated the Mantis Clan's portrayal in the fiction. Hated it. They were teflon-coated as far as meaningful consequences went, and I was somewhat infamous for going, "could somebody hand them a loss they care about?"
So naturally, when I heard the Clan was being removed... I was not happy. Because I never wanted them gone, I just wanted them to get in the grill like literally everybody else (even those useless Crane who I really WOULD just as soon never see again).
 
And when the Mantis playerbase were told,"well, now you get to pick your new identity?" I was not happy. Because they HAD an identity they were happy with. They'd built it over twenty years, with some of the most engagement and unity of purpose I  saw out of any fanbase in the game. I actually tossed out the idea that since the Phoenix and the Dragon had been narrative messes with deeply dissatisfied fanbases, either of them would have been a better choice for, "get blown up, then decide who you want to be as you rebuild."
Hence some of the anguish Mantis fans are still feeling in this age of uncertainty... some Clans had their history inflicted upon them (Unicorn as the Kolat's primary nesting ground, the Phoenix being the Super-Friends Aquaman of Rokugan- useless paperweights nobody even bothered to consider until their one big schtick was somehow relevant, the Scorpion getting exiled so often that they might as well open a timeshare in the Burning Sands, etc.). The Mantis had, for the most part, chosen theirs.

L5R, the old version, has developed such strong feelings for multiple reasons likely.
1) Player involvement in the Story: Many of the things that occurred in the story occurred because of player choice, the world and its many oddities was largely effected and shaped by the players. The new version erases all of those decisions, good and bad, and basically resets the timeline with a few changes. To many this is very painful as they grew attached to the world they helped to shape and create.
2) Clan loyalty: The CCG developed a strong loyalty to ones clan, as it was through there clan that they shaped the world. You would make friends with other members of the clan, interact on forums, have this community. With the new version we lost two clans, The Spider Clan, and my clan The Mantis. So to some members of the community this is a bit of a slight. Some people were so loyal to their clan they would get their clan mon tattooed on them, similar to how some star wars fans would tattoo rebel or imperial symbols.
3) "It has no all or nothing": This is the idea that your not building up your forces for a massive climactic battle (honestly the nest part of the old L5R) instead it appears to be faster smaller skirmishes without any real loss of forces or provinces.
4) The RPG: This really delved deep into the world of Rokugan and allowed for players to be a part of their favorite clan, fight in duels, save the Emerald Empire, and fight Oni. In the later years of the old L5R the Winter Court event began to actually effect the story of Rokugan as well.
5) Cosplay/LARP: This was mostly done at Gencon as far as I know, I sadly never had the opportunity to experience this myself but I'm sure this was another major point of unity amongst the fanbase.
 
Here's the most important thing though. The majority of L5R players are fine with the changes, some celebrating them. Hell even with the loss of my clan I still hope for its return in a future expansion pack. I'll play the game no matter what because I love the setting and I'm excited to be a part of the story. The people who are whining and complaining are experiencing the growing pains and are potentially going through the stages of grief as this is a property that they have been a part of for twenty years. Lets give them patience and time, but if they become nothing but venomous iritents we just need to remove them at that point. I hope instead the venom will work its way out of the system, for them and us.
All in all I guess I want to say welcome to Rokugan, welcome to a land where Honor is stronger than steel. Welcome to a community that will guide and help you throughout the whole of it, welcome to the drama that can rise up from clan loyalty, welcome to the family. Utz!

Yoritomo, just because it would be a fun shout out to the Mantis, and give me some hope. Lol

I've been running Gideon in my group's IA campaign, and we're about halfway through now. Last night after finishing up our last mission, we finally accessed Tier III cards. We were just shy of getting Mak an upgrade for his rifle, and I volunteered my E-11 rifle to sell. I've fired a weapon maybe 5 times so far. So much more efficient to give my men orders, especially now that I can do it twice in an action. 
 
Any other Gideons out there find your personal weapons dusty and unused?

Gideon Argus: Ultimate Project Manager! He uses the twin guns of "grace" and "tact"!

He uses a laser pointer in one hand, a comm in the other....
He's
 
Gideon Argus: Project Manager!