Because it's no longer investing.
It's gambling.
In gambling, the only winner is the house. In this case it's the brokerages.
I hope this helps.
-- BMO
Investing is gambling. Where do you draw the line? You can't. Brokerages win, because they provide a valuable service. How else would buyers meet sellers? Craigslist? Investors sometimes win, they sometimes lose. You get compensated for the risk. Why should anyone compensate you for a sure thing?
All these markets - NYSE, NASDAQ, dark pools, etc. - have their own market microstructures which have evolved to satisfy the needs of participants of the capital markets. If participants or their agents are truly disadvantaged, they will trade at another venue, or simply stop playing the game.
A lot of the proposed "solutions" to imagined "problems" are simply political in nature, meant to benefit some at the expense of others, and will cause more problems than they solve.
Many different venues already have auction mechanisms so that all trades are executed simultaneously at a single clearing price. No one forces anyone to trade stocks in the continuous market. There are lots of pros and cons to auctions vs continuous trading and all other sorts of market microstructures.
Just be assured that any single "solution" you can come up with will leave something to be desired at best.
The less time planning, the more time programming.