Nobody is looking at their whole portfolio and asking themselves, gee I wonder how I'm doing in terms of BTC*? No, it is going to be in terms of USD, along with other USD based assets. A properly diversified trader has no problems with the fact that STEEM can only be purchased through BTC.

Let me ask you this question: Who do you think actually moves the market:

1. Large active traders that have many different holdings and can shift balance between assets easily.
2. People that have to worry about cornflakes (okay I realize this is a little ridiculous sounding, but I mean "others").

The other reason, and it's related to active trading and efficient markets is that any difference that has to do with relative pairs being off (arbitrage loops) will be closed immediately by the market. It's slower in crypto it seems, but it's working. So it doesn't matter if you choose to view steem in BTC, USD, or even Dogecoin, as long as you view all assets with the same measuring stick.

Now it seems that you are referring to chart patterns for reference about how relative values move for BTC pairs specifically, but now it's just boiling down to TA, and well, it might work if enough people believe you, it might not.

*Probably pure crypto traders might do this but due to the volatility it's not going to be useful for them to assess purchasing power without converting out. Maybe in the future.