Sure, telemetry won't inform every product decision and user testing is still valuable.
It does provide insights you won't get from user testing and direct observation, though, as you point out with the usage logs that informed the ribbon design.
> The use of telemetry is marginal to many product design decisions, so there is no reason to force it to every user
If the benefits were purely limited to the design phase, I can see your point for many teams, particularly small ones with niche products where they're less likely to get enough data for it to have much meaning.
But telemetry also has increased value over user testing at different stages of the product lifecycle, like when analyzing what features or products to deprecate or replace.
It also helps for peripheral things like working out what languages localization and documentation efforts should be prioritized for. This year I was asked what five languages a product we make should be translated to. They wanted to start with locales that have the biggest impact and expand to more later. The team who approached me made a list based on support requests and another product in our sector. But our install data showed usage was completely different. We even had two locales that hadn't made the top-10 shortlist. Their guess about the second-most popular language after English was also wrong. By using telemetry we made sure work and funding was focussed where it helps the most users.
Telemetry can definitely be abused or underused, but being on the other side and doing data-driven design and development over the course of a product lifecycle has shown that it has real value.
It does provide insights you won't get from user testing and direct observation, though, as you point out with the usage logs that informed the ribbon design.
> The use of telemetry is marginal to many product design decisions, so there is no reason to force it to every user
If the benefits were purely limited to the design phase, I can see your point for many teams, particularly small ones with niche products where they're less likely to get enough data for it to have much meaning.
But telemetry also has increased value over user testing at different stages of the product lifecycle, like when analyzing what features or products to deprecate or replace.
It also helps for peripheral things like working out what languages localization and documentation efforts should be prioritized for. This year I was asked what five languages a product we make should be translated to. They wanted to start with locales that have the biggest impact and expand to more later. The team who approached me made a list based on support requests and another product in our sector. But our install data showed usage was completely different. We even had two locales that hadn't made the top-10 shortlist. Their guess about the second-most popular language after English was also wrong. By using telemetry we made sure work and funding was focussed where it helps the most users.
Telemetry can definitely be abused or underused, but being on the other side and doing data-driven design and development over the course of a product lifecycle has shown that it has real value.