A lot of the achievements are silly easy to get already,
the whole game is silly easy, compared to how it was previously
so one more wouldn't make much of a difference....
you miss the point. it's not about keeping one achievement hard to get, it's about trying to stop the trend. I know, it will never happen, but that shouldn't prevent me (or you, or anyone else) from stating my opinion.
want 500 achievement points for 3 clicks and 1 minute of "work"? want to reach level 120 in 2 weeks? want to play a game that requires no thought, strategy, planning on your side? want a game without challenges? a game for 5-year-olds? good. this is where it's been going for the last few years, we're almost there.
EDIT: why not expand the original idea? buy multiple items, but why not buy them already upgraded? it will save you even more clicks. just go to the shop, click an item, and in one box type the level of the item you want (e.g. 3), in the other box type the amount (e.g. 1337), the game shows you how much that would cost you and you click OK - TA-DA!!! just imagine the time/click savings!
Indeed, like changing Trading with Indians to Dealing with Indians.
in other words, they are already wasting time on useless stuff nobody asked them to do, let's not start asking for it.