I support the love. PuTTY serves well as an SSH client, many complaints here are about other issues like security, https, trusting binaries, GUIs, and really it's not fair to Simon and team who kindly released the program for us all to use. Nowadays I only use it when I'm unfortunate enough to need to do work on a Windows machine. Thanks guys for releasing this free software.
It's a functional application. It's not well designed. It's not "portable". The hate is because it is so mediocre it's insulting to anyone who uses Windows and has to suffer through it.
If you prefer it, that's fine, but some people expect a bit more from their tools than merely being "functional" no matter how ugly.
It runs on various unixes (without wine), it ran on win32 Alpha (another meaning of the word portable) - I'll give you ugly, but its fully functioned, and arguably much easier to use than the command line openssh-client.
Well designed can refer to more than just the interface. It meets historical windows human interface guidelines too.
I'd also suggest that its an open source project, and could be forked, with a new UI wrapped around the existing pretty good terminal emulation.
I think portable here is referring to being able to run software from a USB drive without running an installer or just being able to download a file into a temporary folder and removing trace of it by deleting the folder when done. I feel a lot of the initial love for putty was the fact that it was portable (and it also helped back in the day that the download was so small, too.)
It is possible as far as I know that it doesn't meet the formal definition in some way, but since you used the term in air quotes and didn't qualify it (like 'but it stores settings in the registry' or similar), I think you may be interpreting the term differently (i.e. I don't think the term is being used to suggest that you can use the same executable across operating systems.)
