If there is no deadline then there is never an incentive to make the change over. Everyone is busy and it could take months to get everyone on-board 12.1 if you let them decide when it needs done.
But if there are a few large players that are having problems then I can see giving them a bit more time. But not setting a deadline is not a good practice. Procrastinator speaking.
May I respectfully ask if you are new to Dash? Enforcement usually begins roughly two weeks after the new version is officially released. In our entire history, there's never been a situation where the network just waited for weeks and months on folks to upgrade. Everybody is given a reasonable amount of time and then the trigger is pulled.
If you read Evan's 12.1 announcement, you'll note that February 12 is the *earliest* date that enforcement can begin:
End users, miners, pool operators, exchanges, and masternode owners have until Sunday, February 12th to update. After that date, we will switch completely to the new version as soon as our engineers determine it is safe to do so, and older versions of the software will drop off the network.
(emphasis mine)
At some point AFTER February 12, as soon as it is SAFE to do so, enforcement will be turned on. As Minotaur pointed out above, this is a hard fork. As of a couple days ago, our biggest exchange (Poloniex) hadn't yet updated. It seems unwise to just kick them (and all their users) off the network in a fit of pique.
But if there are a few large players that are having problems then I can see giving them a bit more time.
I'm not new to Dash. I was only expressing my thoughts out loud. And as I quoted above I'm really ok with Evan's announcement. That's just wasn't the information I remember reading and now upon reading his quote again, I have no issues.
But, I must admit I am confused now about what "enforcement" means or does. Some people are saying that as of yesterday only 12.1 masternodes are getting paid. I thought in order for that to happen, enforcement has to be activated.