why do generation do whistles in d, eflat and f whistls leaving out e?
is there no demand for them?
Not much demand for them, but E whistles do have their place, and I wish more brands were available.
I have a Burke brass pro E, and it’s one of my favorite whistles… I’d never even consider selling it.
There are a few other mid/high priced brands available, but no cheapies that I’m aware of.
I wonder, too. E seems to me to be a much more friendly key for folk music (easier for mandos, fiddles) than Eflat. I like my Water Weasel E, but LOVE my Thin Weasel E. It’s quite possibly the finest whistle I own in terms of sound, playability, and physical beauty.
Susato makes inexpensive E whistles, I believe Shaw makes E’s, too; don’t know about Tony Dixon.
Now if we can just get Jerry Freeman to tweak a few of them! 
I suggest a syn high e, they are very inexpensive, but great quality. The sound is great too, the high e has probably the best tin whistle sound compared to the other keys. For only $30 US you can’t go wrong.
I have an E tube (wide bore) for my elfsong whistle 
Its lovely, all the purity and elvishness of Sandys work in a nice high key. Nice clean transitions, I dont use it as much though, really isnt a whole lot of trad songs that are in E and my church doesnt utilize whistles for most of their E songs (too much rock, no room for woodwinds)
That’s strange, I didn’t know that they did not make high E’s. I get more requests for E’s than high and low G’s combined.
I know Bill Whedon from Serpent Music will make a whistle for you in any key you want. I have 2 now, but mine are both inexpensive ones. I have a Brassy Polly that’s kind of “chiffy”, but easy to play, and he sent me one of his new plastic ones to try. I forget what he called it, and the paper is not here, but it sounds a lot louder and sweeter than the Brassy Polly. It looks a lot like the Brassy Polly but with a longer mouthpiece, and the brass around it matches up with the plastic tube instead of being like outside of it. Anyhow, you might ask him.
Randy Orman
That wouldn’t be the “sweet polly” would it? I’ve been looking for some kind of a review for those.
Here’s a guess as to why there are fewer E whistles than Eb whistles. Whistles have been made mainly for Irish music and the prevalence of Eb and Bb whistles is due to the fashion for tuning up to Eb that some fiddlers favour. If whistles were made in all keys that are commonly used in folk music we would have Db whistles for those folk musicians who like to play guitar in D (or drop D) tuned down a half step. This is not, to my knowledge, a common practice in Irish music. Flat pitch pipes are common, of course, and all flat keys seem covered fairly well except for B.