If you admit that not many people liked it, then what's wrong with them changing it? It was an awfully boring and flawed event. A three hour marathon that was exciting at first but that quickly became a highly mundane labour in which only one or two people reaped the rewards of the hard work of several others isn't exactly my idea of fun or good. Changes like this should have come years ago, to be honest.
Dynamis is no exception as to what requires fewer people these days. A party of six strong players could clear every town zone at 75 cap. I'm sure that just a duo of a RDM + MNK could do it too at 90. Relic weapons are the same as always were. They require an unnecessary amount of coin grinding to complete and the end result is quite mediocre in most cases.
I don't think this patch will "kill" relic weapons by any means. Dynamis was previously on the outs because the gear was obsolete and nobody liked the event. People are actually considering doing it now and AF2 might actually become useful pieces of gear. That's perhaps the most that anybody who liked Dynamis could ever hope for. I think instead of cradling their relics like a wounded child while berating the announced changes, relic holders should embrace what is to come and be hopeful. What I would like to see is the difficulty of obtaining relic weapons be mitigated while also adjusting the strength of their weaponskills and perhaps increasing the frequency of the triple damage procs. Honestly, relic weapons were mediocre before Abyssea, it just took a while for people to catch on.