Not all villains care about Spider-Man and those who do, tend to have different goals. You could also ambush him in costume, no reason to know his identity. And why would he want to make a name for himself, he only makes himself a target for all the heroes. Gang members don't make a name for themselves by killing cops, that would be dumb.
You would only need the contingencies in case someone with a grudge is on the loose. As Spider-Man is able to handle the Sinister Six by himself most of the time all that is needed is a careful observer who calls in backup, almost every hero could do it alone and chances are there are more than one available. Just because a known criminal is hiding, doesn't mean no one is looking. And why wouldn't he just kill random people, if he dosn't know Spider-Mans address, Peter will turn up at some point. Killing family members is not a priority for most villains.
The protection would be, for the most part, indirect, because if everybody knows who Spider-Man is, so do the heroes. If one is hurt (including loved ones) the others will at least avenge them. Sure some villains might not care, but you can't guarantee protection ether way. If a villain kidnaps May and Spider-Man is not there, other heroes won't go out of their way to help her, if they don't know who she is.
Also I didn't say he absolutly had to tell his identity to everybody, just Avengers and SHIELD would be enough. Telling friends and family would be good as well, so they can make decide for themselves, if they have enough protection.
A secret identity will be uncovered by someone at some point. Typically the hero will find out to late, so it will become a massive liability. Would you rather be prepared as much as possible or hope for the best when that happens?