I don't get your point. Why does summoning exists in this game then? Why is the Co-op community so vibrant on PC? You're contradicting the facts with some strange theories. "FROM not wanting x, or y"? C'mon.
Also:
That wouldn't happen. What I'm suggesting is getting your stats all they way down to match the host. Even if you have the max Hexes or Miracles, your stats would be severely downgraded to the point where it feels equal to the summoner.
Souls Memory is even worse because it doesn't matter if I don't level up and permanently stay as a SL 30 character. If I keep Sunbro, my SM will raise to the point where I will have to start yet another character if I want to help noobs to beat the first bosses.
My point is that a SL 150 character summoning a SL160 character to help with a boss is still going to have a challenge because the person their having help is at a similar level range. They in most cases can't just summon someone to help and sit back as they do everything because the boss gets a slight buff as well.
A SL 12 character summoning a SL 200 character can enter a boss battle, then their summon could hit them with a powerful hex and the end - boss battle over, never even attacked or had to avoid an attack once. It makes what was a fun, engaging battle on the old system trivial on this new one.
Regardless of the above, I thought you were saying a universal summon for anyone at any level to summon anyone else at any other level - no other changes.
If you're saying drop stats then I've already explained what I think the problem with that is - people create builds which are heavily dependent on having high stats and for them to be arbitrarily dropped so you can be at the same level as an opponent could mean not being able to use weapons, armors, magics, hexes, or miracles that your entire build could center around.
For example, I like to use the Giant's Club, which requires 60 strength. If I got matched up with someone who's soul level was 100 and my strength dropped sub-60 as a result, I couldn't use that weapon. If I got matched with someone soul level 20, I couldn't use the Giant's Club, or my ultra Great swords, or my King's ultragreat sword.
If instead you're saying keep the stats the same but just completely neuter the damage, then comes the question of how do they neuter it and how much is reasonable? Getting summoned to fight a boss where you've got ultra good weapons that are doing a pitance of damage doesn't really seem like a good compromise at all either.