I've been lurking the forums for quite a while but this point is so unbelievably baffling that I could not help but create an account just to address it.
1. Stationary strikes are not more powerful than strikes where you step in. The basics physics should make it apparent that if you put your body into your strike you carry the extra momentum and force with you. If you have played football (=soccer) five minutes in your life you know how much more power you get in your kick if you move into it rather than literally just stay still and swing your leg at it. Some of the most legendary KOs (Bisping Hendo comes to mind first) are from guys taking big forward steps to put their whole weight into the punch. A lot of the "stationary KOs" are more big counters than just brute force (Rampage vs Wandy 3, Rumble vs Teixiera).
2. For sake of clarity, what exactly do you consider stationary? Using UFC 3 as an example, stationary lead body kick results in your character just lifting his lead leg and smacking the opponent, whereas the forward lead body kick has him take a step with the opposite foot, then throwing the kick. If you are talking about a guy stepping into his strike then that is not stationary by the game's logic. I would accept the premise if the logic was to decrease the vanilla power but increase counter damage which would then prioritize landing quick strikes over long-winded loopy ones but you still run into the issue of guys fishing for counters.
If anything, I would rework the forward strike so it only involves a small step forward (as how FNC did it) rather than the weird jogging movement that body straights most notably have. That way stationary jabs would be just arm punches meant to occupy your opponent while forward jab would resemble what GSP used to do in his jab decisions.
3. This would completely break the balance of the game. If you have ever played any traditional fighting game, the rule of thumb is that faster strikes deal less damage (and in those games, have less reach too). Combat sports games are practically simplified fighting games (which is not a bad thing) and a lot of footsies concepts apply to both MMA game and real-life striking so I think the comparison is very fair. Speed and damage are considerably more important than range. That's why people hardly throw kicks in the game.
The main thing that people pre-patch complained about, sway strikes, were literally standing strikes that were faster and did more damage than regular attacks. People weren't lunging forward with them. Similarly, body knees and elbows were a thing even without the forward momentum. Closing the distance is not difficult at the moment, so why would the aggressive fighters not just get in your face and use stationary strikes? I don't see how that is any different from them swaying in your face while you try to counter sway them back. Seriously. Using your argument of "the guy coming forward risking getting countered" is the exact same thing that happened when they went for duck uppercuts, as they risk getting sway hooked.
4. People will always play aggressively. Playing aggressive results in quicker matches and therefore quicker ranked process (why win 1 decision when you can go 2-1 or 3-0 being aggressive in the same time frame). Even FNC, which people rave about, was filled with Mike Tyson players who spun around and tried to get big counters off. The same way guys in UFC 2 tried to get in your face and do 1-2-kick mixups. The issue is less severe in UFC 3 because the ranking prioritizes winning matches over playing matches but still.
5. I think the actual issue with super aggressive playstyles is that it is considerably easier to execute it than it is to defend against it. If you want to reduce it, then make it so the attacker has to make outplays and be efficient or he suffers severe penalties (e.g. give whiffed sway strikes more stamina drain or increase the body/leg vulnerability to a point where doing it predictably costs you).