Many Star Wars fans hate the crossguard lightsaber. I can understand why, even though I love the saber myself.
People who hate the crossguard saber say they don't like it because it is not a traditional lightsaber- but then again, Darth Maul's wasn't all that traditional, but it was still pretty bad-ass, just like this one. Also, people say that the cross guard is really dumb and futile, simply because the person wielding it may commit Darth Vader V.S. Luke Skywalker-type hand suicide by cutting of their own hand by swinging around the darn thing.
However, a video on YouTube by a YouTuber named ThegnThrand proves that it's completely safe- as he twirls around his makeshift lightsaber with cross guards that are coated in fresh paint, to see if any would get on him (simulating a wound or injury). He also fights another dude to prove its advantages. Check it out:
After watching this, one might conclude: Man, that is one heck of a lightsaber.
People who like the lightsaber simply say that its a bad-ass looking saber, has its advantages, and is a fantastic Sith/Dark Side lightsaber.
One may also realize that since this movie is a new start, per say, without erasing the history of past Star Wars movies, unlike scenarios like the Toby Macguire Spider-Man series being erased from the MCU, and almost all the old Bat Man movies being completely ignored as of newer movies, that many things would be different. So, you would think that upon starting new, the creators of this movie must have wanted to design a new, cool lightsaber with a twist, and the newness and difference of this movie from the other movies affects the opinions of Star Wars fans everywhere in both positive AND negative ways. Han Solo dying pissed off a lot of people. Rey being the main character pissed off a lot of sexist Star Wars fans, and fans who just prefer the main character to be male, and aren't necessarily sexist. But, debates such as these are booming all over the internet, as well as the opinionated discussions on Kylo Ren's Lightsaber.