You've probably read it, but Jameson Lopp write interesting argument about this viewpoint. Here's a part of his argument.
[1] https://bitcointalk.org/index.php?topic=175996.0
He makes a few fair arguments in there.But wait, you may be thinking, wouldn't quantum "miners" have earned their coins by all the work and resources invested in building a quantum computer? I suppose, in the same sense that a burglar earns their spoils by the resources they invest into surveilling targets and learning the skills needed to break into buildings. What I say "earned" I mean through productive mutual trade.
[1] https://bitcointalk.org/index.php?topic=175996.0
Quote
"Quantum recovered coins only make everyone else's coins worth less. Think of it as a theft from everyone." - Jameson Lopp
This is true, and many other points raised are good. However, there is a existential level risk of establishing any precedent of freezing any kind of UTXOs. A much bigger risk than most people are able to understand. If the solutions to this problem all remain controversial, and many users do not support them,then what? Try to force the update, which would significantly aggravate the negative impact from this precedent? 
This is why I am not necessarily trying to say that I don't want them to be frozen under any conditions. I am trying to say that if they do get compromised eventually, that it is not as bad as many parties try to make it seem and that we need to work on reframing this problem. How different in practice is this from someone's key being compromised because their source of entropy was bad? Very little. Keys do and will get hacked all the time in one way or another. Not in the quantity that is talked about here but it does happen relatively often and we are fine.
It would be easily if we could reach strong consensus, but this is not going to happen with these kind of proposals that involve freezing. How we approach this lack of consensus will have a bigger impact on Bitcoin's future than any amount of "stolen coins" could ever do.