Lots of people and companies have made tube compressors in a pedal shape, but very few have done it successfully IMO. The main man at Godlyke told me in an email that Guyatone discontinued their tube comp pedal because they decided they were not able to make it good enough within an acceptable price point. And EHX's Black Finger is so inconsistent, with some units being decent and other units being garbage, that I think EHX also has severe problems with the quality-to-cost ratio. CAE came up with a very good design, but the product was so expensive that nobody bought it, so it got discontinued. Whatever Retrospec "did right" is clearly neither easy nor inexpensive to do. I'm betting that's why they stopped making them, too. And most people, at all levels of musician or studio, are not going to put a $1000+ tube device on the floor and step on it. They want their expensive tube compressors safely housed in a rack. Rackmount tube compressors sell very well.