If your network is so about to fall apart under load, or so broken due to network issues, or your servers are so overloaded that you start seeing appreciable packet loss with UDP internally at a site, then chances are the last thing you want is loading your system even more and slowing things down by retransmitting samples that are obsolete in a couple of seconds anyway....

Serious exceptions, sure, retry. But serious exceptions are rare. What's not rare is sampled memory usage, cpu usage etc..