Now I don't know if what has been quoted here as being from Lord Kelvin is accurate or even true. So let's get that out of the way first of all. Still, this webpage lists several erroneous statements that is attributed to Kelvin that obviously aren't true, or even accurate, anymore. Certainly the part about physics being a dead subject isn't true (if only he is alive today to see how that is so not true).
Still, how is that any different than the grandiose claim that some physicists have made regarding "The Theory of Everything", even when, admittedly, such a theory can't come up with a description of everything, such as many emergent phenomena.