To me we are talking about different things. Street fighting is too dangerous because there are no rules and because there are no safety measures (referee, doctor, paramedics, rules & regulations about the surface they are fighting on, pre and post fight medical tests etc.).
MMA is getting lamer (not lame, I love it regardless) not because of rules and regulations, but because of bad rules and regulations.
Good rules & regulations: Are ones that take extremely dangerous stuff away, that take unnecessary dangerous stuff away and keep the fight somewhat entertaining. All this without altering the actual core which is one on one fight. Now we had a match where neither guy won the FIGHT but other guy clearly won the MATCH. To me thats corrupting and altering the core which is the fight.