[G6Tanuki]

Pondering this, I wonder - in the US UHF TV took a long time to get off the ground - to the point where it was considered very much an afterthought to TV designers until well into the 1980s. Remember, unlike the UK they had 525-line NTSC colo(u)r on VHF from the 1950s... so no real pressure to put much effort into UHF... and UHF doesn't cover US-style distances well either.

I also ponder whether the US FET TV- and FM-radio tuner designers were more focussed on coping with lots of strong competing stations on VHF [particularly on the VHF-TV and 'Band II' FM broadcast radio-band] whereas in more-regulated State-controlled-media Europe we tended to have many fewer stations. Cross-modulation resistance (hence early use of MOSFETs and diode-mixers) could have been more important to the US designers? When I visited Dallas/Fort Worth in the early-1980s tuning a FM radio from one end of the band to the other revealed precious few unoccupied channels.

Then in the context of base/mobile two-way radio, I know that US designers from the 1960s onwards had very rigorous targets to meet for handling high power adjacent-channel signals without desensitization: a typical US Police low-band [30-50MHz] mobile-radio installation in the 1960s had a 100-Watt transmitter and the base-stations were often Kilowatts.
Minimal pre-mixer gain [often a grounded-grid FET, or a high-current bipolar] and diode-mixers were the order of the day. The front-end of a similar-era Pye Westminster [with a humble 2N3819 or two up to a low-oscillator-injection 2N3819 first-mixer] just wouldn't handle it.