Examples: the mobile app is very clunky and slow, the in-car dashboard devotes half of it's real estate to a visualization of the car's object detection, serving no purpose other than to distract the driver.
It's fine. But the problem domain of Twitter is dramatically different than anything Tesla engineers are working on.
The cockpit is all nice and shiny, but not having any haptic feedback for any kind of regular controls you'd use (switching media, A/C control, etc) is a very questionable choice and a worrying trend among automakers in General. The center screen in the Model 3 to get something as basic as your current traveling speed seems equally questionable from a safety perspective.
I've also seen my fair share of Tesla summon close calls on the neighboring parking lot.
When it comes to the app, Tesla owners seem to have a broad spectrum of opinions. Personally for a car as expensive as a Tesla, the quality of the app would be the last thing I'd care about as I would consider it absolutely unnecessary.
The main thing where I totally agree Tesla is absolutely ahead are OTA updates for car firmware. However, looking at it from a security standpoint, bad security practices could really backfire and from a privacy point of view I'm not a fan of permanently internet connected vehicles either.
For balance, there have been bugs - the linking of key fobs to driver profiles has always been glitchy, and Tesla’s decision to use an inadequate eMMC chip was shortsighted given the volume of data logging. This caused issues for a few owners when the chips started to degrade over time. But to Tesla’s credit they later offered a free chip upgrade to all owners, and even covered the costs of those (like me) who got a third party replacement.
I rate Tesla’s software engineering. I’ve had years of issue-free OTA updates and sheer pleasure from driving the car. And having access to the car via an API is cool too :-)