1. Not trusted. Simply put Bitcoin has value in the market place just not with any of the vendors or people i want to do business with. My local online classifieds returns 9 ads that mention Bitcoin, out of about 100,000 new ads a month. 9. Two years ago it was 15 hits, so trending to zero???
I actually don't believe you it's lower than before - can't be. Adoption is in constant rise. Are you sure about it? Some URLs?
2. Not portable. Setting up my phone wallet is scary as hell and most certainly not close to mainstream yet.
Not that much complicated.
3. Not fast. I cannot complete a person to person transaction in less than 20 minutes.
Still faster many other means of wire-transfer but I agree, this is one of the weakest points. Hope it can be solved in future.
4. Not scalable. If I solved 1-3 above, the network would fall on its face.
I think this is FUD. Everything is solvable, code is changeable.
5. Not anonymous. Not a huge deal but nobody is tracking what I buy at garage sales today if I use the good 'ol dollar. Imagine me buying crap from a guy that turns out to be thief and a drug dealer. Nice eternal paper trail i have left behind.
Completely anonymous if you're using it through Tor.
I think it will take 10-20 years of software improvements to solve our current problems, and in the mean time.... I think the price will go lower. Maybe even for years.
I say max 3 years.