I like some quests to need multiple people to do certain things. Everyone knows of the various quests that do this. I enjoy running the necro quests where you have to split up...although you really don't need to split up it is different and fun.
Leave the quests like they are. Leave it so a very few quests do require several people. We are talking about a handful of quests and if you don't like to group or can't find a group...np don't do that quest. Why does Turbine have to cater to every single crowd on every single item? I understand that groups are harder to get (I argue this as I put up an LFM at all hours and NEVER have issues getting 1-2 people to join) and I understand some people don't WANT to solo. No biggie there are tons of quests to run that you can solo so leave the VERY few that require people alone so that those of us that like these quests still do them.
Hell I don't like Delirium but I don't ask them to change it just because I think its kinda lame...I just don't run it.