If they are from "other people's" events, maybe you could give the tapes to the corresponding other people! I bet they'd love to have them, and then they can transfer the tapes themselves if they want to keep the footage.
For myself, I wouldn't just toss them without transferring them first. People grow up, grow old (if they're lucky), and die. The only video we have of my dad (not so lucky) is a brief few soundless seconds from one of my grandpa's old films my cousin transferred. You never know.
And some people still do use VCRs to tape TV shows (my friend and I do!), so instead of just sending the tapes to a landfill, maybe Craigslist them or something (depending on how many you have).
Good for you on the decluttering! Something my house desperately needs but it's just such an overwhelming job... :)