Ale is beer. I believe this is what @Smid was commenting on, that “beer” was being used where “lager” was intended, as “beer” already covers “ale.” Either that, or the OP is being somewhat redundant by mentioning “ale.”
For me, yes, pretty much all types of beer should have some amount of head. Some, like lambics and other sours, tend to have a very thin to non-existent one. Others, like stouts, are properly poured with a thick, creamy one. But, yes, I like pretty much all styles with some amount.
Well, I guess that’s unavoidable I suppose, even if a tiny head, the one I was thinking of is being shocked by being served a pint of real ale in Reading about 87, the foamy head was there above the rim of the pint, but it was foam and was gone in a couple of seconds. The beer was to the top. It was lovely though. It’s the way it’s served in the South of England.
I’m not sure how widespread it is, and traditional, but I think what I’d call “creamflow” was widely used about then. The process of putting the beer through in effect a small sprinkler to make it creamier (and potentially have a head too). It’s normal for standard bitters nowadays over here in the UK, but I don’t think it was always there.
If I get a pint with zero head on it (U.S.) I immediately suspect…something. Flatish beer, dirty glass or I don’t know what. It just doesn’t look right. I generally prefer lagers but with all the craft ales out there, I’ll try anything. Re: Guinness - isn’t the bottom of the head supposed to be right at the top of the harp or something? I went to a Guinness pint pouring contest a few years ago and seem to remember something like that. $5 got you all the Guinness you could during for the duration - maybe a couple of hours. That’s the kind of contest where everyone wins.