Why? That just wastes everyone time. It clearly doesn't help solve 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.
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.