I guess in the strictest terms Silver Age was a reboot, but I don't usually consider it one myself. The reason that was so successful, was that it wasn't really 'replacing' anything. Outside of Superman and Batman, Superhero comics were dead and gone. Green Lantern, Flash, Justice Society... they were out of print for between 5-10 years and they'd moved on to the crime/western/romance comic waves. There wasn't really the case of one month you're in the middle of reading a character you've loved for 20 years... and the next month everything you knew was discarded for some 'hot new thing'. It was a pretty unique situation that turned to gold for DC.
'forced' is a strong word. They really didn't NEED to do anything of the sort. Marvel has had just as many continuity glitches over the decades... and they just ignore them and kept doing what they do. They need to just accept their glitches and move on. DC has way too much Legacy... and Way too much history to cram it into a sliding timeline and NOT have glitches... they need to just stop trying to 'fix' things.
Remember... Parallax wanted to reboot the universe and make everything 'perfect,' and DC insisted that was BAD thing.... STOP BEING LIKE PARALLAX!!!