It does ramp up in difficulty, it's just that the starting point is pretty fucking high on the difficulty/power curve already. I have only managed to get past round 1 a few times with randoms, and round 2 is definitely harder. I see why they did it, they were tired of people bitching about burning through the content, so they slowed down progression (fewer sources of powerful engrams) and made this activity scaled for very high power level players. Kind of a lazy solution to the problem, I think, but at least I understand why.
I think it won't be as much of an issue as more people get to higher power levels. The more annoying issue that won't change without a fix from bungie is the stupid matchmaking, where a fireteam of 3 spawning in to an instance pretty much guarantees that only one or two other players will randomly spawn in, and since there's no way to do 6-man patrols, the crowdsourced solution is to go in and spam random people asking them to invite your friends (and then sometimes to leave afterward, especially if they are lower light). In some cases, people are apparently asking blueberries to invite their friends to get more people into the instance and then getting them to make one of their people the fireteam leader (hey, just promote so-and-so, they can send the other invite, so you don't have to type it in), at which point they kick the poor blueberry to make room for more of their friends.
when your matchmaking/fireteam setup encourages that kind of behavior, you dun goofed. Of course, the bungie solution would probably just be to disable messaging people not in your friends list.