You're being very overdramatic. First of all, you were the one who made the decision to put effort into collecting shinies and event Legendaries to begin with. It's not something that you *have* to do to play the game (unlike Nature/IV breeding and EV training). And, second of all, you wouldn't really "lose" all of those Pokémon, just like you technically didn't "lose" your Lv 100 Charizard or shiny from Gold (unless your cartridge batteries died, of course). The older games would still always be there with all of your older Pokémon, and you'd make a new collection of favorites on the new ones, just like you did last time.Ok let me try this one more time you must get my point at the very least
I have 17 shinys 3 of those are events from b2/w2(creation trio) one is an event from x/y (shiny gengar) A shiny slyveon i breed for a gabite, and haxorous from b2/w2 a shiny garchomp I randomly encountered in platnuim shiny gyrados from hg, a shiny mudkip I breed for ( and others I can't remeber), I have a mew from the emerald event (traded to me) I have jirachi deoxys diance from japan ( and others such as the pokebank celebi) If I was unable to transfer all of this I'd be pissed beyond repair its more then losing my lvl 100 charizard or that one shiny I found in gold, its a combination of pokemon from as far back as fr/lg, I have every legendary catachable since fr/lg and guess what they're people out there how have more then I do they're people with boxes of shinys (likely hacked but whos to say someone out there doesn't have that many shiny pokemon) have all event pokemon maybe even a living pokedex waiting to be transferred to gen 7.
Now tell all of us that all those pokemon can't be transferred to seventh gen because they want to make the games as simple as they were in red and blue, I garuntee 90% f of the older fanbase will be gone, and some kids who even have those pokemon (kids can get event pokemon too) will be just as angry if not more since they won't know how to cope with it and you just lost the audience you got in x/y leaving only the kids who have never played pokemon that's a major sales drop.
we're not talking g/s anymore where you miss out on mewtwo ho-oh lugia and some shiny pokemon we're talking years 12 years worth of pokemon collecting down the drain it's more then losing your first starter it's losing everything the games had it would be a regression, and by doing that they ostracize the older fanbase the one part of the game that isn't easy as heck is taken out because kids don't know how to breed (but probably have an older sibling who knows how) its not losing those 1000 hours you spent playing red/blue and gold/crystal its losing years of playing the game.