What is it with all these people who think “logon” and “logoff” are verbs?
Yeah, what idiots.
ETA: Or are you complaining about the spelling (logon as opposed to log on)?
What do you think they are?
People do it alot. Nevermind. It’s a lost battle.
And what is it with people who think “alot” is a word?
Heck I used to work for a company where the English and journalism majors that made up the Technical Documentation Division insisted on using “input” and “output” as verbs. I guess that’s become accepted usage. But they also insisted on making the past tense “inputted” and “outputted.” The latter I never understanded.
Additionally, dictionary.com has the following advice:
I don’t know why, but I kind of wince when I hear logon/login used as a noun referring to credentials.
Since I’m not seeing an actual question in the OP, let’s move this over to IMHO.
Colibri
General Questions Moderator
Is “whoosh” a verb?
Yes. People don’t write that they are “logonning,” or that they have “logoffed,” so why do they write that they “logon”?
Today, I onlogged so that I could upload my input, download the output, and offload it all. When I am done with that, I will offlog.
You really should offshore your inputs so that you can downsize the oncosts of your upkeep.
Because language is an organic and ever evolving thing. It will always be full of odd quirks and changes. Why do people use the words “overwhelmed” and “underwhelmed”, but not “whelmed”? Why do many people think that a food package that says “MICROWAVABLE” is normal, but if it says “OVENABLE” that’s just totally weird and wrong?
I wonder about these quirks of language out of curiosity; it’s really cool to see how and why words (etc) fall into or out of use. But it’s a bit silly to pass some judgment on these changes; for every usage you decry, there’s one you use that was hated by earlier generations. And so it goes. 
It’s not just logon. I’ve lost track of the number of times I see this when proofreading a document: “We’ll get that setup in the next day or two.” Or “I’d just like to followup with another question.”
Makes me wince every time, but what can you do?
They’re obviously adjectives. “Look at that logon horse! Over there, by the logoff cow.”
Related question: Should I say “logon to” or “log onto?”
“Log on to,” obviously.
That depends on whether you say “log off of” or “log offof”.
These aren’t the same thing. This isn’t about not using a prefix. This is about how the past tense of logon is logged on, and the past tense of logoff is logged off. This indicates that people still think of them as two words instead of one. So why do they spell what they think of as two words as one word?
The answer is simply that they computer terms, and the command to accomplish them, like nearly all commands, did not have spaces. The same thing happened with setup when used as a verb. In fact, if “set” was not the past tense of “set”, I bet people would would not say “I previously setuped” and would instead say “I previously setted up.”
And, in case you are wondering, logon can work exactly like setup, in that it can be a noun. Logoff probably could, too, if there were a noun associated with the term. (A logon is your username and password–i.e. the items you need to log on.) And both can work as adjectives. (cf “The logoff procedure for Facebook used to be really complicated.”)
Oh, and to answer your question: there was no need for a verb form of oven, since bake works just as well. The microwave, a new invention, needed a verb, and the default verb for something is to just use the noun as a verb. The other choices (“nuke,” “zap”) are currently too informal. If they become formal through constant use, I’m sure “microwaveable” will sound just as weird then, too.
I suspect that’s what it is. FWIW, I write technical documentation and use “logon” and “logoff” as nouns or adjectives only (e.g. “logon credentials”) but “log on,” “log onto,” “log off of/from,” etc. as the verb forms.
It’s just one of many losing battles, though.