I would also argue that changing the deck size by cutting 15 cards would turn some people off of the format due to having to reconfigure all their decks.
It wouldn't run me off but I would be very annoyed redoing all my decks because they decided to change the format so that someone can shuffle easier. The format has been around for a long time and you're the first person I have ever heard make this suggestion.
I don't break my deck into two and shuffle like that and neither does anyone in my playgroup (we have between 4-8 of us that regularly play together).
And I'm not too sure you're right about the 100 pack sleeves back in the day. I know that all I could ever find was 60 or 80 sleeve packs because I always joked with the LGS owner about how he raked in money on the EDH players having to buy two packs. Ultra Pro didn't put their Eclipse sleeves in 100 packs until 2-3 years ago because the Command Zone made a huge deal about it.