"IAM represented Fleet service workers at US AIRWAYS enjoy an IAM National Pension Plan benefit of $78.30 a month for each year of future service." Well, that's at best misleading.
What if the plan actually flops like other pension plans have?
To the first part, you're right using one take of logic. Applying that logic I'll take every penny of additional pay you've received past what was promised in the CBA in effect when you were hired. Things change. What a defined benefit pension is is a guarantee BASED ON THE AGREEMENTS FOR THE RELEVANT YEARS. If, as happened, schedules are reduced, then future years of credit are reduced. Based on your dumbass logic if the benefit was INCREASED then we wouldn't see the increase either.
To an extent you make a valid point about the plan becoming insolvent. IF the plan goes under you're entirely right. Of course the same can happen with Social Security, and we're not professional investors, so the same can happen to our 401(k) as well, in addition to the risk of a fund in the 401(k) being run into the ground. There is no surefire retirement plan. The most secure way is to just put money in the bank and not get a decent or useful return, hoping that the bank doesn't go under when you've got more then $200,000 (or whatever the limit currently is) in the accounts.