I do, but I think it comes down to whether you philosophically consider money from the Government (well, money from your fellow taxpayers) as being a bonus in general, rather than an entitlement.
Entitlement is a very loaded word at the moment, and I don't mean it in a derogatory sense - purely in its literal meaning.
So from that perspective, I personally would see FTA in the same way that I would view free use of a dentist - something which I will use, and which will benefit my family through no real effort of my own. Whether it's because it's assisting my family's dental hygiene, or putting electricity in our wires and food on our table.
So I view a payment linked to vaccing in the same way as I would view the Government (or whoever) deciding what types of leisure activities they make available at no cost. Some I will choose to benefit from and participate in, others I will not.
And IMHO opinion a lot of it comes down to what is mainstream.
Family X lives on a main road.
Family Y lives on a side street.
The Government decides to spend $Zm to re-seal all the main roads, for super (or rubbish) reasons.
Is it fair that Family X now has a spanky new road, and Family Y still has a pot hole covered one with gutters that flood, further damaging the roads (and their homes) periodically?
The Government now decides that it is good for people to live on main roads, and are introducing a financial incentive for people living on them.
Is that discrimination, in and of itself?
Is that discrimination if Family Y can't afford to move to a main road?
Is that discrimination if Family Y specifically don't want to live on a main road?
The Government then decides that enough people are living on main roads, and they remove the financial incentive.
Is it fair enough if Family X complain about the reduction of their family income?