lots to address...
1.) Taxation as a margin of ROI having a significant impact on investment decision
Depends on who is investing. Megafirms (Berkshire, Fidelity, etc...) have to show gain in their funds. Say your 401 is in Fidelity, their "buckets" need to show gains to keep people investing in the bucket. They however don't care about taxes because it's filtered in fees to the customer, who pays the taxes anyways.
Your average day-trader is buying and selling at a rapid pace and is more interested in small gains that cover the fees and provide enough margin to make the next trade.
Then you have a guy like me who looks for long term growth investing. Market shifting doesn't matter so much as buying at the right price and holding it for ages. This same guy will also buy a junk stock to hold in reserve, take a beating and then use it as a long term loss to cover other long term gains for tax purposes.
Then there's the Romney kind of guy that is just parking money in investments since the interest rate is so low right now that it makes no sense to park your money there. Dividend growth (if measures as compound interest) is astronomically higher than any investment that is FDIC insured. There's no reason not to have your wealth invested as opposed to a Scrooge McDuck money vault.
I think the main problem here is that you're confusing investing with gambling. And that you truly don't understand investing as a concept beyond "buy this stock and sell it later, hopefully making more money." Your example of people handing you money and you giving it back has literally nothing to do with investing.
2.) What are the purposes of tax?
Seriously? To pay for the infrastructure and protection that govt provides for you. Or as Rush would have you think, wealth transfer. Because, you know, buying shit isn't an upward wealth transfer or anything like that...
Certain tax codes are also there to incent behaviour. Why is there a mortgage interest deduction? Because we want people to own homes. There are a lot of transaction involved in home ownership that shift a lot of money around. This looks good on balance sheets and makes rich people a lot of money if they own CDOs from the 90's until about 2010.
As for why revenues were still up despite lower taxes, volume vs. margin. Even during a recession here we have GDP growth. Shit man, revenues are STILL up. Now, imagine the "debt crisis" that we happen to be in at the moment being lessened by what is, by your own words, a non impactful tax increase.
3.) Fortune 500 hoarding cash
Unintended consequence of the stupidly low interest rates. Debt is a hell of a lot cheaper now than it has ever been. The second part of that story that isn't often advertised is how ugly balance sheets are right now. Ever heard the phrase "house rich, cash poor"? Flip that around and that's what you're looking at currently. If interest rates ever go up, you're going to see a massive unloading of that cash to pay down debt.
That bit about "persistent worry in the recovery" is absolute rubbish. We're regularly trading at 80-85% of the high watermark of the DJIA. The major problem right now is stalled growth. The solution is going to be a chicken/egg contest between just enough hiring to spur some demand and then more hiring to start making more supply. For the supply siders out there, your theory is now junk. There's plenty of shit to buy, nobody is buying because they're paying down debt as much as possible and hoarding cash in fear. For the deman siders out there, your theory is now gold. There's a lack of demand because the supply siders figured if they squashed out enough labour cost they'd win with supply.
4.)
The primary goal of investing is to gain money
Not always. Sometimes it is to loose money to cover gains elsewhere. Sometimes it is for influence.
Why is this so hard to understand?
Good question.
But just for shiggles let's take your statement here and apply it to #1. If my goal is to take $100 and turn it into $100,000. Taxation as a margin of my goal in getting to $100k is irrelevant. It's a cost of operation, not a barrier to entry.
To assume that someone will stop attempting to make more money because operational costs go up is an absolute canard. If the end goal is $X, everything along the way is just an associated cost. Let's get away from taxes for a second. Let's say it's just me and my e-trade account trying to get a 1,000% ROI. Somewhere along the way, the trade fee goes from $5 to $8. I don't just say shit and decide to never make another trade. I hold to cover. Why is that so hard to understand?
And there's much more but I don't want to write a goddamn novel here.