...looking at the AK one day touring plan and the One day combined AK and DS touring plan, it says to get there 1 hour before rope drop on busy days and 40 minutes otherwise. Considering June is fairly busy, it's safe to assume the op was admittedly there 45 minutes later than suggested... how does that constitute bad advice on the part of the UG?
Well, it's hard to criticize the "arriving an hour early" part of the "two parks in one day plan" with one major exception - most people won't find the pace very enjoyable. In order to do both parks in a single day would definitely requiring skipping a few things and keeping up a pretty fast pace - difficult, quite possibly not enjoyable, and downright impossible for some in the hot Florida sun especially in summer months. Getting up at 6 or 6:30am to be at AK by 8 and rushing all day to finish up with Fantasmic after 9pm makes for a pretty tough day. And AK requires a LOT of walking by most people's standards. By the time you're back to your room at 11pm or so you're talking a
17 hour day in the sun, heat, and humidity.

This is a vacation, right?
My other comment on all such "arrive an hour before rope drop" plans is that during our past visit earlier this June the result was waiting in a rope drop queue for a very crowded surge(edited from "mad dash") to the prime attractions. Not all of us can or are going to walk as fast as the rest of the crowd from the ropes to the first attractions. Kind of pointless if 500 or perhaps even a 1000people wind up passing you on the way to the first attraction.
BTW, what's the difference between waiting at a "rope drop queue" vs an attraction queue? If getting there an hour early only results in cutting the overall waiting time during a day's visit by 30 or even 45 minutes vs arriving at opening time, it isn't an efficient use of time. If it cuts it an hour it's a wash. Personally, I'd prefer to sleep in another hour while on vacation. To make a park at 8am, an hour prior to rope drop, means getting up at 6 or 6:30 if you're me, the type that wants/needs time to S/S/S, an unrushed cup of coffee, a decent breakfast, etc. We bagged the "prior to rope drop plan" after the first day after talking to guests at other parks that said that all the parks were simply very crowded from the get-go. It was far more "productive" to be in the parks during the last hour than the first.
I honestly think managing FP's well is a bigger key to more enjoyable touring than getting there an hour early. We found that getting another FP BEFORE riding the matured FP attraction, especially by sending the best, most willing walker(s) ahead to get the next FP's right at the "allowed time" works really well. My DS16 and I split the "FP runner" duty and neither of us really minded it as we are fast walkers and it made everybody's day more enjoyable. We spent 5 days total in the parks(2 at MK), and two half days each at TL and BB. During our entire trip, June 6 thru 13, he longest line we waited on was an hour for Soarin' and 45 minutes for Peter Pan.
I will admit/suggest that AK and Epcot are best done in the morning unless you are an on-site guest and go to an evening EMH. Soarin' and TT FP's are usually gone by 11:30 or noon, but if you get there at 9am you'll be able to get FP's for both though the second FP return time will be later in the day. We got to AK just before 9am opening and went on all the major attractions by 3 even though it was mobbed at rope drop according to CM's and guests. There are "lulls" during the day at all the parks around lunchtime, parades, shows, dinner, etc and even right after T-storms that can be exploited. And if there is a T-storm coming in(keep an eye out for the weather), use that time to wait in an indoor standby queue at an indoor attraction. This worked for us several times. For example, we waited standby 45 minutes for Peter-Pan at MK but it was during a T-storm. We stayed dry and got in an attraction while our SM FP's matured.
If you go to WDW during peak times, you are simply going to have to wait in lines at times. Duh! Arriving an hour early MAY cut the wait time for the first attraction if you hurry on over, and you'll get one FP with a reasonable return, but don't expect miracles after the first hour. Everybody seems to be going early. Our experience was that the last hour in the parks were much more "productive" -
and FUN - than the first.