Are you more interested in fixing a process or fixing the problem?
Sending in-product feedback certainly could work because it's more likely to be seen by product management as it continues to roll in.
Support-driven product change requests are well intentioned but generally break down as a process internally. The working knowledge base and incentives are not properly aligned.
> Sending in-product feedback certainly could work
If it could work, we would have seen that happening. We have not, so we must assume it can't. Thus, asking to "send feedback in-product" is just a way to waste everyone's time. You avoid the negative stigma that is associated with knowing a problem exists and ignoring it, without having to undertake any concrete action. Corporate spin at it's finest.