It’s not cynicism, it’s simply people telling you that you are a newcomer to the field and that the basic idea you are proposing was tried and rejected decades ago. This happens a lot when anyone tries to propose new ideas in relatively mature fields.
It’s possible that something was missed in this area, of course, and that those old ideas should be revisited! But as a basic rule of thumb, if you want to resurrect an old idea, you should first go back and understand why people stopped using it (some of the reasons were summarized by @antoine-levit for you). (Maybe those old reasons for rejecting it are no longer valid due to new developments, or maybe you can invent a variant that circumvents the problem!) If you don’t do that, then you are likely to waste a lot of time rediscovering the same difficulties.
PS. In density functional theory (DFT) for solid-state physics, the steepest-descent ODE approach is called “molecular dynamics” energy minimization, and it was largely abandoned by the 1990s in favor of nonlinear conjugate-gradient methods; see e.g. this review article. There are “damped” dynamics variants or “momentum” corrections (as they are called for stochastic gradient descent algorithms like Adam), however, that turn out to be closely related to conjugate gradient, but IIRC they tend to have more specialized uses (e.g. optimizing noisy functions).