So do I. It is actually not the point. Either we consider them useless, in which case we should refuse to use them and oppose them because they provide a false sense of security. We should then think of alternatives.
If we consider them still a bit more secure than plain http, we should use them, without getting naive and thinking that they do wonders and without stopping to still think of alternatives.
The actual exact level of trust we have in them is quite irrelevant in that sense. To just elaborate briefly on it:
If I use
http, anyone, anywhere even on my LAN, going upwards all the way through the internet all the way to the download site, could mess with my downloads. Anyone, without special clearances, courtorders, connections etc. All they need is access to a router, server, wifi network or lan or actually just cable that i am communicating through. They don't even need to be very skilled, because there is plenty of software out there to do MITM attacks readymade. They don't even need to mount a collision attack in md5, because they could just change the checksums file to send me another hash. It couldn't be simpler actually.
If I use
https, like when i downloaded fedora yesterday, then the weakest link was fedora's https. So anyone managing to crack that would be able to send me whatever they want basically. If we just omit the very real life risks of poor server implementations and poor security attitudes of people using https for a moment, coming to the trust of CA's, than basically it is conceivable that a government or a big economical power for my part manages to obtain a false certificate from the root CA. It is hard to assess this risk without being either naive or paranoid because we know very litte about the CA's, but I think that realistically speaking it would come down to either getting a court order, which probably needs a specific investigation etc, which becomes a rather far fetched risk when it comes down to downloading an operatiing system. Or it comes down to stealing the private key of the CA without them finding out, which is difficult to assess, we can only hope that CA's and the auditors do some effort to make that hard to very hard. Or it comes down to having the CA giving out false certificates which means they are completely betraying all their users, their policy and lying about it, because at least Go Daddy and Verisign
claim that they never even had such a request by a law enforcement agency.
All in all, I don't trust CA's, but if I realistically assess the difference in difficulty of sending me tampered with stuff over http or https, and the number of people having the means of doing so, I would say there is a big, very big difference between the two.
For those who now start to write me to ask me how much i trust the people on my LAN, I can assure you that I have tightly wrapped them in tin foil, so I should be fine.