Complexity of Dendrobium Phal. type Breeding?

[Wrebbitrocks]

Hands down, my favourite of all the genera are the Dendrobium alliance in the Phalaenopsis types. They put out large showy flowers in return for the amount of effort they require. They are also upright and don't take much lateral room as they like small pots, last long, and they just happen to be carefree for me.

What came to my attention is that they are so hard to find and are expensive compared to the dime store phals. The color range is narrow too. I've been longing to find a nice clear solid yellow or at most some white with a full round form. All I find are greenish yellow at best and the nice yellow ones have very thin segments and aren't very showy and all with a dark lip. The flowers of their finicky cousins, however, like chrysotoxum, aggregatum, fimbriatum, densiflorum, harveyanum, and hancockii to name a few are amazing.

The question I have is, why is the breeding with these so hard unlike the extreme ease of crossing between the species of other genera/families like cattleyas, phals, and oncidiums etc. why are they so hard to come by and if it's at all possible to do crosses between species?

What would be the challenges to producing a clear, solid yellow flower with a nice round/full form? I was thinking maybe a white phal type dendrobium or at least a yellow one and cross it with something like chrysotoxum which has the most resmblance to a phal type because of the canes and the arching spikes of flowers from the tips instead of individual stems from the canes themselves. Is it possible at all? What would be the obstacles and what would prevent me, genetically, from producing this cross? And, what would be the easiest cross, if it exists, to produce said bloom.

Thanks to all of you who know how to answer this.