Reciprocity

You wrote:

... we're more likely to respond awkwardly ...

I guarantee you that the root cause of this is that we do not really believe that the compliment from the other person is sincere. This is bred from the McDonald's/USA retail culture of "have a nice day". This is rooted into the general falsehood of today.

You wrote:

Could it be that we tend to shy away from this because there's a fear of a reciprocal obligation? Or perhaps there's a feeling of infringement on our autonomy?

Probably both of these. On the first, as a child we think we have all the time in the world, but as we grow older we realise that we cannot be everything to all people so must use our time and love wisely.

On the second, a child loves all the attention it can get. But as we get older we tend to want our "own space". Again I think this is because we realize that we have a finite time and want to spend it achieving our goals, we realise that we can exist on our own without attention from others.

So it appears to me the root of our not wanting to connect (as adults) to the love offered in the above two examples is a recognition of one's own limitations and one's own mortality.

But there is another reason. Perhaps we don't accept love because we don't want to hurt the person giving us the love? When we are immature children we don't realise the pain that our accepting all the love from the other person does to that other person. But when we grow up into maturity we notice that if we accept this love, and we don't want to reciprocate that love (for any number of reasons) then we end up hurting the other person. So we decide not to accept their love.

You wrote:

I would fall into the category of people who for whatever reason resists "giving in" to the love that God offers

Question: how would you know if and when you had given in to the love that God offers?