This is a mixed bag, the truth is that these issues are considerations at all levels. better players than myself can like softer rubbers or slower blades, I know players who are worse than myself who like much faster blades and players better than myself who do the same. So for me, it is less about playing level but what are the properties of the equipment that facilitate how you win and lose points.
But when it comes to spin generation, to me, it is very obvious that some rubbers have more elastic sponges than others at a certain deformation speed, which can be desirable under certain circumstances and so desirable under others and it isn't a matter of hardness, it is more about sponge compressibility/elasticity. And while some players use pips, it is really not a serious subject of debate to point out that certain properties are going to make you work harder, especially not having a sponge that plays like it is boosted. That is what many are really saying when they talk about a rubber being too soft for pros, you don't have to be a pro to experience the same issues, the rest is tradeoffs for your style. The point in using the pros is to talk about the limits of the rubber and what direction one goes in when using it.
Yes, at all levels we sort of, give some brain capacity, to it. And we, sometimes, try to express our feelings about a certain rubber, truthfully. And even though this is relevant for us, and truthful, it is much less relevant for most other people reading it. And, especially, any kind of attempt of generalization about our feeling is best described as wrong. Well, I'm not trying to say that all we say is relevant only for me (person speaking), but rubbish for everyone else. Sometimes, occasionally, we can derive something useful from other persons description of a rubber, especially if we know, how he speaks about other rubbers.
So, I'd say:
Point 1. It's a mess. I don't enjoy D09C very much on the FH, and NDH likes it even on the BH, and it is just fine. I like Glayzer on the BH, and Gozo only accepts Zyre. You say D09C has better spin and top-level speed than G09C, and while true, for others G09C is better, because the extra safety is more useful and they still have enough power to get from G09C the speed to finish. It is simply maximally personal.
Point 2. Even the, sort of, accepted generalizations, like pros tend to use harder rubbers, are wrong. Yes, as I said, on the abs. top-level, they do, but even in the top 1% many simply do not. The generalization is wrong, in that top 1% level, and much more wrong in the majority/average level.
Point 3. The brain capacity we, here in TTD (judging by the thread titles) give to rubbers and blades, is, to be honest, perverse. I consider myself a bit of an EJ, because when I compare myself to the other players in the 2 clubs I train with, I'm definitely like top 5% of EJs. I mean, some have specific hard-held opinions, but most are very much more oblivious to the equipment, and that is super good I think. Even though I have ideas to "help them" with suggestions, they don't give a shit, and that is actually good. Btw. and I speak about both players worse and better than me. And, my level of EJ, in compare to the TTD standard, I'd say is low. TTD is very much about rubbers and blades. That's why I like exceptions, like say dingyibvs, who focuses on technique, and I like the fact that the TTD team mostly sends videos with pros, which is not about equipment primarily. To summarize the point 3 - there is so much potential in technique and movement and serve, and yet, we speak mostly about rubbers ;-)
Cheers, see you "there" ;-)