Hi, Dkding,
The first dimension...
If a particular product falls short, you should be able to provide feedback the author can act on. You should easily be able to do this without comparing to other products. Each product is unique, and may take a different approaches to the same problem. So, describing what you want in terms of another product is not meaningful feedback.
For instance, Singular handles a lot of boundary conditions that most other CRs fail to address. This handling of boundary conditions may cause a small loss in DPS for Singular, but it prevents a myriad of problems that are encountered in the PvE world. Comparing Singular to any other combat routine is almost meaningless for all practical purposes.
With PvP combat routines, some may be prepared to do battlefield analysis, threat assessment, and crowd control. While the more simple ones go straight for maximum DPS. Again, these two types of routines cannot be meaningfully compared.
The second dimension to product comparisons...
Fanboi's will immediately jump in with their typical 'contributions'. This usually rapidly degrades into insults, flames, and causes posts to be deleted and threads to be locked. As moderators, we see this happen time-and-time again. The blanket rule of 'no comparisons' shuts down this useless trolling before it even starts.
The "no comparison" rule is not something the Moderation team will consider relaxing. So, if you've feedback to give, do so without comparing to other products please—its not difficult to do.
If you find yourself attempting to compare to other products...
You probably just want to use the 'other product', instead. As, you obviously feel it is superior in what you deem important. There will never be a 'best' CR that can do it all. Again, this is a consequence of design decisions made for the individual products. Each design decision that creates a 'strength' for a particular product also introduces weaknesses somewhere else. This is the fundamental nature of design. You should embrace those decisions, and help the author improve them in the context of the strengths of the existing product.
cheers,
chinajade