Great answer JHB! I especially like the part about assuming the worst when drafting the by-laws.
My first time around on the by-law review committee, I served with two people who went in assuming that everybody would always act with the best interests of the PTA at heart. Not me. Every time I saw a potential problem in the by-laws, I asked how these would work in the face of two hypothetical groups: the "Association of Angry Pawnee Parents" (AAPP) and the "Secret Society for the Preservation of Personal Power in the Pawnee PTA" (SSPPPPP).
When we were done I was confident that, if necessary, our PTA could continue to function in the face of the agenda of the AAPP. At the same time, I knew safeguards were in place that would allow the "Coalition of Concerned Pawnee Parents" (CCPP) to unseat the SSPPPPP.
I'm not a Roberts' Rules expert, and it may address some of this. But, I'll answer from my own version of "common sense rules".
Your bylaws are the official rules of your organization. So, no, you shouldn't suspend or ignore them when they aren't convenient. However, you SHOULD amend them as you discover the need for changes. I'd recommend you follow whatever your process is for an amendment.
This particular rule could be too constraining, as you've discoverd. I've seen it left in, but modified two different ways.
One, instead of a word like "must" or "shall" (have served), you can go with "should". This indicates a preference but not a requirement.
Two, is to leave the rule in place, but add an override option.
"xxxxx, unless otherwise approved by a two-thirds (2/3) majority vote of the membership present at a general meeting."
(It might just be a majority vote, it might be 2/3.) Sometimes statements like this are added so that the BOARD can approve the override. How much of a majority, and whether the Board or the General Assembly should vote depends on how critical the issue is.
For me, I imagine the worst possible scenario (maybe a core group of officers taking too much control) and try to write the rule so as to best safeguard good decision-making in the future.
P.S. Be sure to read your bylaws carefully to make sure you don't already have an override provision you can exercise.
Our president quit so we need to replace her. We have someone on the board ready to step in but our by-laws say that in order to be president, you have to have served on the executive board for at least a year, and she hasn't. Can we suspend the rules since no one on the executive board wants the position? Do we have to go before the general membership to do this? Help!