I think the reason you find so many people calling tops -- and doing so with such incredible inaccuracy, is that most people have no idea what to look for. I'm only just beginning to learn myself, and I've been at this a while.
Below are two charts which I have made in MSFT Excel. They are based on the "internals" figure known as "net new highs," which is a snazzy way of saying new highs minus new lows.
The contrast between the two is intended to do two things:
[1] To give you a clue about what tops look like. (I say give you a clue, not to be sarcastic, but because I am, as I said, just learning this aspect of the market myself, so a clue is about all I can promise you.)
[2] To illustrate that even when this market tops out, it may not crash and burn the way so many perma-bears on this thread seem to think. In fact, I will be a bit surprised to see a correction of more than 10% before the next upleg. (I would not be at all surprised to see a few months of sideways action in a trading range before the next upleg.)
Anyhow, this is all JMDO, and anybody who commits actual money based on the say so of a small, fluffy, white doggie, (no matter how adorable that doggie may be), is a fool who deserves to be separated from his money.