actually, they shouldnt. What they should do however is change scaling so that lvl1 missions fade out after you reach about 1.5 standing, forcing you to move on to lvl2 if you want to further increase your standing.

I made 3+ standings from nothing more than grinding lvl1 transport missions and quite frankly, i havent done that many of those either.. Sure the lvl1 missions start to fade out around 3.0 standing.. so it took an eternity to get from 2.7-2.8 to 3.0, but we are talking about lvl1 missions here, so that fade-out should have happened a whole two and a half points earlier, around the 1.2-1.3 mark.

How it should be in my opinion:
-> Missions give you their full relation increase while you are in their relation range. That is 0-1 for lvl1 missions, 1-2 for lvl2 and so on.
-> relation increases start to diminish once you cross into the treshold for the next level and reach 0 about halfway through to the next level.

Also the rewards (both money AND items) should be properly scaled, so it is actually worth doing higher level missions, as sometimes the rewards of those are not in line with the increase in difficulty and travel time, when compared to lower level variants.

To illustrate: let's say i can choose between lvl1 transport missions and lvl3 bounty missions. Which one should i choose?
- The bounty mission requires me to go to a remote location, kill 5-10 bots, gather their cargo and return home. This will pay somewhere around 60-120k depending on the mission, but let's assume 120k for now. It takes me 5-6 minutes to get there, 5-6 minutes to get back and say 10 minutes on average to get enough kills. So what did i accomplish?
In 20-25 minutes i earned 120k NIC, 5-10 kernels, some fragments and loot and some relationship increases. That assuming nothing went wrong.. we are talking about a lvl3 mission after all, and soloing those - while easy if done with care - is prone to hickups resulting in catastrophic results.

Let's take a look at my alternative, the measy level 1 transport mission.
- It requires me to take 3U worth of cargo and move it to the station next door. Sounds simple, is simple. You can do it in about 5 minutes or less. But wait, you can do more transport missions at once and you don't even need fancy gear for that, just a simple industrial bot that has 7.5 cargo. Then you can do TWO missions in those 5 minutes. Each such rune gives you about 22k NIC, 2*35 = 70 ammo and standing increases from two missions. You can do 4-5 runs in the time it takes you to do one bounty mission, which nets you a whopping 100-110k NIC, 350 ammo and 10 standing increases of similar magnitude as the single bounty mission gave.

So at the end, you get more stuff from doing the simpliest level1 mission, than from doing a level 3 one. Now THAT is a problem i would say.. the level 3 rewards should be waaaaay ahead here.. hell it should not even be a question, if its more viable to run lvl1 missions than level 2 ones, let alone level 3.