I agree that EMM had nothing to do with what the OP encountered. I would bet that 99% of the guests lined up to enter the park at 9:30 had no idea what an EMM was, much less that there was one scheduled that morning. So the theory that they arrived early because of it just doesn't hold up, IMO.
One other question -- you said you parked at the Contemporary because you had a dinner reservation that night. Did you use valet? Or did the security guard let you in the regular lot 9 hours early for your ADR?
I'm still curious about your timing. You said the GS line for your AP took a half hour, and you arrived at the MK at 9:30. Even if a long security line took 30-40 minutes to get through, how did that add up to 2 and a half hours???
You are entitled to your opinion, as I am to mine. Simply sharing my account and thoughts, wanted to know if any others had the same sort of experience on EMM days and vent a bit.
Since I didn't have issues in May with the same sort of security/entry backups for rope drop with the enhanced security in place, came to conclusion the likely variable was: the crowd arriving earlier than usual due to EMM happening that day
I certainly could be off in my reasoning or it was a cluster of issues, time will tell if more post the same experience here. I love most things Disney, warts & all but don't necessarily drink the Koolaid. If I observe what I feel is an issue, not afraid to post my thoughts here and engage in a healthy discussion. I'd like to think I was wrong in my assessment, but am not convinced. When others who have actually participated in same situation (arrival time on an EMM day) report their experiences, then I may change my mind.
As to your specific concerns with the timing:
I checked my watch when entering the security line, it was 9:30 am, a little over an hour later I was re-directed to the kiosk from the normal GS line by a CM with a tablet. Starting to think I should've refused. I had already texted DH, back at home to share re the long wait. Going by my text time, and fact we were getting 'close' estimated the total of that portion of wait.
OT - my DS, in his early 20's, was pulled every single time we entered a park for extra security, which never took more than a few minutes. He had no issue with it, nor did I, but we assume he fit a profile or just looks shifty.
The 2nd line took longer, probably not that much more than the first, but it 'felt' much longer at that point. when I finally was face to face with CM @ the kiosk, checked time again to relay it to DH. That's how I knew that portion of GS wait took 30 minutes.
Didn't take long to go thru turnstyle, no more than 10 minutes. Walked into park a little before noon and headed back for BoG ADR.
Since you are paying close attention & following my time line very carefully, I'll let you do the math as to estimating the over-all time I spent in the GS line lol.
This had NOTHING to do with it being an EMM morning and EVERYTHING to do with when you attempted enter the park.
Most guests will try and get there as close to rope drop as they can, but will often run late. Others will say they don't want to deal with the hordes on Main Street for rope drop, so they wait to arrive until just after rope drop.
Either way, that makes the 9:30-to-11 a.m. block the most soul-crushing time to get into the park. And that had nothing to do with the EMM people who were through security and into the park two hours earlier.
It was Sunday the 14th, but I've never really noticed a huge surge in what I expect are normal crowds (via experience and crowd calendars) on the weekends except for F&W.
Not sure our souls were crushed (interesting way to put it btw) but it was indeed deflating and set the tone for a less than stellar park day, especially for my family who doesn't visit as often as I do.
For those who inquired as to my parking status @ the CR, thank you for your interest

. Of course I used valet, which is perfectly permissable btw for those who are hoping to open that can of worms. Have watched from my CR room balcony a car being towed away a few years ago. Often stay @ BLT these days and glad they keep an eye on the parking as it's easy to find a spot to self-park there. If only they would be a bit more diligent at VWL, where we have spent a lot of time searching for a self-parking space. Don't get me started on needing to pay for valet @ BWV most stays since it's such a small lot and I won't park in overflow.