I do not think that having an offensive metagame is bad, and I don't see where people get the notion from that stall MUST be an apparent strategy. If the metagame revolved around defense, it would be BORING, plain and simple.
With that said, though, even my very limited experience is enough to note the differance between an "Offensive Metagame" and what exists now. Offense is facillitated by not only a huge range of ridiculously powerful pokemon with ideal base stats and movepools to back them up, but also the evidence of weather (really, I don't get the point of sneaking around it. Abstract or specific, the point is still the same, though being direct is obviously the more efficient mode of communication. I do understand your point that tagging along weather will invite preconceptions, but that will happen whether or not the topic of said conceptions is stated explicitly) which boosts water and fire moves respectively a further 1.5x their base power. If Keldeo uses hydro pump in the rain, even resists are taking essentially a 120bp move AFTER the fact, and that is absurd. Though water is the more ideal offensive type, the same applies with things like Victini's V-Create: resist or not, something is taking a 180bp attack (if not double that if the switch in does not resist). These are absurd damage outputs for such a small and almost integral amount of support and so I feel as if weather is the most dominant force in facillitating the less than desirable metagane that currently exists.
Another issue that spawns from the difficulty in walling the aforementioned attacks is the infamous reliance on match-ups. While I have virtually no experience playing in OU, in the many battles I watched the results were almost predictable from team preview, and this is not a good sign in what should be a skill-based game. Yes, some archtypes will always fare well against others, but why are we facillitating this even further by allowing weather to thrive? With weatherless teams matchup is still apparent, but it isn't as easy as "x beats y." It's moreso "team 1 is somewhat weak to pokemon x but it can be played around by keeping y and z healthy," etc. and this in itself is placing more of a reliance on skill.
I am obviously very new here and have done virtually no competitive battling, but from the months I've spent lurking and watching battles, these are the observations I have made, so take them as you will.
In response to those who believe that too many threats, not weather or other offensive aids, are responsible for the poor metagame, I have to disagree. Take out the controversial support options and what do we have? A specs keldeo? A scarf salamence? A rock polish Landorus? Keldeo, with such a large damage reduction, can be easily handled by just a couple resists. Once the need to deal with weather boosted attacks is diminished, we no longer have to run 4 water resists, so we are able to consider pokemon that check the other large threats, such as the two pokes mentioned. As Princess Bri noted in her thread, redundancy should be avoided if we hope to check as much as possible, and with the NECCESARY redundancy of having so many water resists out of the way, we are able to check even more, helping to diminish the issue of team matchup, among others.