Were they kind? Maybe, but clumsy. How do you feel now, knowing that there will always be someone with 20 years more experience than you, that you can't compete with? Neah, it was not pure kindness.
Did they try to prepare for negotiation? Using arguments like "we have candidates 20 years more experienced than you, so you cannot ask for too much money"? Again, clumsy. You can say this when the offer is on the table, no need to give a warning to the other party in the negotiation 1 week in advance, so he can prepare for such argument..
Most probably you will not get the position and they will not feel bad that they did not choose you, because "he was such a nice guy, but we did not let him be disappointed, since we gave him a good reason that he cannot be guilty about this interview". In other words, they told you so, so that they don't feel guilty about you.
Your take from this? Nice experience, learn something and move on.
If they call next week though, then they probably failed the negotiation with another candidate, so if you like to take a risk, ask for more money than you initially thought to ask, as they may feel weaker in the negotiation for fear of losing you too.