One of the main problems with this policy is the concept of 'fairness'.
Fairness and equality are the two words that are dominating this election most apart from the word Brexit.
People have very different reactions to the two words. Inequality tends to be viewed more negatively - especially amongst older votes - and its the word Corbyn uses, whilst May talks of fairness a lot more. This idea of 'ordinary working families' having a fair deal.
This is one of the reasons that this is going down like a lead balloon in many quarters. Its perceived as unfair and is in conflict with the rest of the message that particular type of voter who likes May.
In their eyes, they have done everything right: worked hard, saved hard, provided for themselves and have tried to provide for their children. Many believe they have already paid for their social care needs. They have been responsible. They have been 'perfect citizens'. This is what they planned for and what they were led to believe was the way to behave and do. Its pure conservatism really.
So taking away from their family the security they thought they had built up, is 'unfair'. It throws a curveball at what they thought was a given and makes them feel aggrieved.
Instead of tackling the problem that actually our society has misjudged and underestimated costs to help people understand why this policy is even being proposed its come out of the blue to many. Even though the problem has been known about politicians for ages, this hasn't really been communicated to the public well. The whole thing needs to be better explained to the public. Which is no small task.
On top of that the policy is actually unfair in how it affects some but not others. Which only amplifies anger about it.