I think they're OK when they are used to populate a separate, one-off set of tables for things like logging, aggregation etc. for security or creating metadata for example.
When you start altering your "live" data or "looping back" into your biz info tables, that's when they become evil and unwieldy. They are also utterly unnecessary for this. There is nothing that a trigger does that a stored proc cannot do.
I feel like they are SQL's evil equivalent to GOTOs in programming languages. Legal, but to be avoided unless absolutely necessary, and they are NEVER absolutely necessary.
