At least last time, I think I got an error message when I tried to do that.

Edit: Tried it with this one (there are only about 8 items that apply to me, and of those two don't bug me very much). You have to rank all options...so I will not be voting.

To be clear, the non-issues for me are:
-Call center staff not knowledgeable: I've gotten the occasional dingbat, but usually the VX, VS, and Amtrak staff are pretty good (especially on the premium lines).
-Calendar inaccurate: This has always been "need to refresh browser and make sure I'm looking at what I think I'm looking at" for me.
-Change fees: My change fees are waived with VX, it's $50 for VS...Amtrak has issues but those are a bit more related to *ahem* disclosure issues than the fees themselves.
-Low-level award not available: VS and VX-with-partners are basically fixed-level awards. VX internally and Amtrak are (generally) tied to price-of-ticket-in-cash so this is a non-issue as well for me.
-Mixed segments price at highest class: Huh?
-Multiple seats on one flight not available: I'm single and if I'm traveling with friends we have no problem taking different routes/planes and rendezvousing at our destination. Actually have one trip where the only time I'm with my travel companions en route is for a few hours at LAX.
-No one-way booking: All four of the FF programs I participate in on some level (VX, VS, and SQ for airlines and Amtrak) allow one-way booking.
-Segment-based redemptions: As opposed to? VS and VX are pretty straightforwardly this and it doesn't bug me. Amtrak shifted to this and that doesn't bug me too deeply. I think there's a case to be made for zones and for segments as the basis of awards (both have pluses and minuses vis-a-vis one another) but I have yet to get actually "stung" by this. The closest was the collapse of super-long-haul awards on Amtrak with the AGR Derailment...and most of my furor there, again, has been at the BS involved.

And as I said, the inability to indicate that the biggest pet peeves (no award chart/calculator and programs carrying out devaluations) is actually a pet peeve of mine about IBT's surveys.