There were better justifications back then though. Stuff ran on completely different hardware and layers of abstraction weren't really workable. Some of the BASIC was more or less compatible but then again most stuff was machine code and BASIC was usually just the OS's terminal and bootloader of sorts.
One could not reasonably expect the same software to work unchanged on a MOS 6502 based computer like the VIC or the Apple ][ and in a Z80 based computer like the TRS-80. And there were many more differences at the hardware and ROM-kernel level that made cross-platform software largely unworkable.
Apple kept the bad old days alive with its own intentionally locked-in ecosystem. Maybe if they had failed more spectacularly in the 90s then perhaps today every company wouldn't be using iPhone lockin as a goal to aspire to.
Around 1980 you'd buy an Apple ][ or a TRS-80 or a Commodore VIC and they all were incompatible, although most of them still had Micro$oft BASIC.