Edit: 50/50 and guessing isn't new in Sf game, SF4 was full of vortex, unblockables, 50/50 mix ups.
So let's do a little history lesson on the Street Fighter series when it comes to stuff like this, because you're not wrong about vortex. Street Fighter 2 was a game that lived and died by gimmicks and vortexes. SF3 was a game that also had a pretty strong emphasis on oki with things like Oro and Urien. The top tiers in 3S like Chun/Ken/Yun/Dudely etc. all could end a combo in a vortex situation and kill you outright. That's nothing new.
What people complain about regarding "50/50s" in SFV generally don't get into knockdown mix up. That's just kind of something that's going to happen in Street Fighter games (I'll get into SF4 specific stuff in a bit and why it's an exception). The real 50/50 mix up type stuff people aren't liking tends to be the standing mix up with how throws and strikes work. That's new to SFV. In ST and 3S, strike/throw mix up was there but it wasn't a really strong 50/50 situation. In SF2 throw protection is pretty insane and most characters have pushback and other things to stop that nonsense. It's why some of the best pressure in SF2 is just plain fireball trapping or standing at length and doing low rush punch. In 3S it was a lot stronger, but it took like 10 throws to kill people and parry+other defensive options blew it the fuck out.
SF4 is where it gets a bit weird though, because throw protect and pushback weren't as wild and you could generate + frames with anybody pretty easily. You could stay in somebody's face awhile and pressure. On the flipside of this, you didn't really see that happen too often because defensive options in SF4 are actually insane. If you were any good at SF4, you knew the list of anti-pressure options. Crouch tech in 100 different ways, backdash, focus attack stuff, lots of invuln reversals, invuln reversals + FADC. Whenever somebody blocked in SF4, the complexity of the rock/paper/scissors and mindgames in general went pretty far. It did get a bit too much where defenders sometimes had too much advantage, but it was not just 50/50 type stuff.
The 50/50 vortex stuff in SF4 people complained about was actually the result of an exploit on knockdown. This was where SF4 got a bit weird because this exploit meant characters who didn't have strong oki before suddenly could unblockable loop you. It was so prevalent that match ups were often decided by whether or not a character specific unblock set up existed or not. While 3S had bullshit unblockables too, the way that exploit worked didn't mean Chun was going to suddenly put you in this weird grotesque situation. That was the real issue in SF4 vortex 50/50 stuff. It became everybody's gameplan at some point in weird esoteric ways that weren't fun or interactive.
Anyways, back to standing pressure nonsense. In SFV, the standing pressure looks a lot like SF4 but with the major exception of Crush Counter existing and defensive options being garbage across the board. Once you generate plus frames on block and go through the list of defensive options to worry about, it's pretty slim. As a result, a lot of the times if somebody blocks a standing hit you just kinda get to do it. Worst case scenario is generally an EX reversal which is pretty whatever and can result in your opponent dying anyways. So as a defender, instead of thinking through pressure and looking for an escape you're really just trying to avoid getting CCed, which is the biggest issue in the game atm since CCs can just outright kill you.
That's pretty abnormal for a Street Fighter game, and it's not really fun to engage with for most experienced players, Most characters in the game put you in a basic RPS situation where your best option is to just RPS them back if you block. On top of that, the neutral game is a bit more limited and is encouraging players to get up in somebody's grill and go for that. That's where the comparisons to Mortal Kombat come from. That is a game where you generate plus frames that turn into actual 50/50 high/low stuff without real options to deal with it sometimes.
Anyways, where I come from is an arcade with people that have been playing SF since 1992 who say a lot of the same things about SFV and SF4 I talked about. I did a couple years as an esports journalist in the FGC and interviewed top players all the time and that's about the gist I get out of them on shit like this. There's always some personal preference in there to people who don't like generally integrated setplay (read: SSF4 Ibuki), but that tends to be on a person to person basis.
