From a technical / legal point of view, this is a terrible, bad idea.
(Don't get me wrong, nice and easy, seamless integration to move steem in and out would be awesome)
BTC is under attack. All govern-cements are trying to regulate or ban it. Being physically tied to it could mean costly litigation. Steem right now is mostly in the "imaginary" realm right now, and so can weather the coming storm by staying out of the way.
Technically, the encryption on the wallets in steem are not up to snuff. It is good enough, because there are people who can reset the chain. But, it is no where near good enough for the attacks that go on BTC today. So, at minimum the developers would have to enact two party authentication, and then would have to lock down part of steemit to do the BTC-steem interaction. And, the developers wanted steemit to be replaceable; just one view of the steem-chain
Security on scaling is an issue like you say - as it regulation. I mentioned both in my Steemit SWOT analysis post yesterday. Thanks for your excellent feedback @builderofcastles and NOT being an echo chamber ;-)
Gone to read it.Damnit @mindhunter you post too much, I totally missed your SWOT analysis! :-p
I know - I post like a mad thing! I always keep forgetting to post my source images too! I'm finally getting into the groove 10,000 posts later though ;-)