I guess it's hard for me to understand that mentality. I started reading super-hero comics with Superman #50, which not only was the 50th issue, but also the 4th part of a 4 part storyline, which crossed over with the other Superman titles. Granted, it was the engagement issue, but being issue #50 didn't stop me.
I branched out from there and grabbed Flash #50 and Green Lantern #9.
I just don't buy the argument that the only thing preventing people from picking up a title is that it isn't a #1 issue. There have been plenty of series that I picked up in the midst of their runs. Again, the internet makes it easy to figure out which issues you need and which you can ignore.
And, as Guy said, picking up comics after the 1st issue makes people want to go back and buy the previous issues, which drives up back issue sales (good for the comic store), as well as the trades (good for bookstores, Amazon, the comic store, etc.).
Which isn't to say that I'm against restarting series, mind you. I do agree that a major change in the title is a valid reason to restart it. However, I think comic companies have been too liberal with restarting a series. If the protagonist or the very essence of the series changes, then I can see restarting it. For example, my previously used example of Superman and Justice League restarting after Crisis on Infinite Earths and more recently, Green Lantern restarting with Hal as the main character, instead of Kyle after Rebirth, represent times when I think it was worthwhile to restart.
Over at Marvel, restarting and re-titling Spider-Man, when Octavious took over made sense. Same with their restarting Daredevil, when Waid came onboard to move Matt from being a dark and serious character back to a troubled, but more carefree character.