I did not say crit isn't important, i said haste and mastery are better for you then crit.
And bell is a good trinket,but it is the worse caster dps trinket in raids that you can get, i will try to explain why.
First of all, rawr simply puts it as the worst trinket,and rawr tends to be correct. Also a very good site i use for over 2 years Maxdps clearly states it.
Also i was trying out a lot of trinkets, because there is no BIS trinket list on the internet that i could find.
First using Stump/bell- second using Stump/heart of ignatius and my dps was 300-600 dps higher using stump/heart on 5 different tries each.
The second reason why i think bell is bad is because i dont like proc trinkets. Use trinkets are better imo because they offer you more controlable burst and not some random proc. Sure, if your a newer player and can'r remember to use a trinket every 2 minutes or so, proc one is good. But i used bell for 2 weeks and it often procs when i dont want it to, just as any other proc trinket.
Sorry for bad english