If you currently do 40k DPS, and the boss has 1.5M HP It takes 37.5 Seconds to kill him.
If we reducing every by the same factor say 100.
You now do 400 DPS, and the boss now has 15000 HP, it still takes you 37.5 seconds to kill the boss. So nothing changes.
I think most people could live with a change like this. You aren't losing any power, you not any weaker than you were, stuff you could do before you can still do. You can still powerhouse your way through old tiers just as you do now.
Unfortunately, that is not what blizzard proposed when first discussing the item squish. They proposed to lower the item levels on the earlier tiers (4-6) by a smaller amount, and the later tiers (11-13) by a much, much larger amount. What this does is severely affects your power. What you can currently do now, you might not be able to do in the same capacity. If you are a Fury warrior for example you might have to now DPS in your tank gear, as you do not have the HP to live long enough to kill the boss, where as currently you can kill him in your DPS gear, or and hopefully it doesn't come to this, you now have to bring additional people as you now lack both the DPS and HP to kill the boss before they kill you.