Why does abandonware exist?

https://infogalactic.com/info/Abandonware

Why does a Company keep EOL software proprietary rather than either open-source it or alternatively sell it to another company? Maybe because it would give the other company a competitive advantage?

Does a company make any money at all from abandonware?

Why did Adobe abandon Flash? if Adobe open-sourced flash, I highly doubt it would lead Adobe to crumble.

Why did Adobe kill Macromedia Freehand rather than open-source it or alternatively, spin Macromedia back off? The latter should have been to comply with antitrust laws. Or kill Illustrator but before that, provide customers a seamless transition to Freehand?

What benefit is there of abandoning software? What benefit does abandoning software bring to the company?

Why doesn’t Microsoft make Windows Gold, a unified Windows combining every single feature that ever existed in any Windows version? from Active Desktop in Windows up to XP, to Edge, Cortana, and Windows Subsystem for Linux in Windows 10? Combining every feature of every Windows version that ever existed? You think it would be clutter?

Software should never be abandoned. It should either be continued, made open source, or sold to another company.

Can software be re-continued? Resume development?

Feel free to answer the above questions in the comments section below.

Computer ideals

For desktop, workstation, and small to medium-business server: tower taller than wide and somewhat deeper than tall.

Four cores on desktop, laptop, or entry-level server.

RISC for mobile computers, CISC for desktops and servers. ARMv8-A for smartphones and tablets, x86 for desktops and servers, and either ARM or x86 for laptops.

2U or 4U rack for medium to large business server.

Half or somewhat less preferred full height blade in a 10U blade system for enterprise.

In NUMA, either have four nodes each with two processors for a total of eight processors, or eight hot-plug SMP units each with four processors or 16 hot-plug SMP units each with two processors for a total of 32.

Flash memory for mobile computers and laptops, HDD storage for desktops and servers. Maybe dual drive SSHD and SSD for all-in-one desktops and hybrid-flash arrays for tower desktops and servers, but dual drive works for tower desktops as well.

Hybrid-flash array with a few small NVMe SSD’s and many large SATA or SAS HDD’s. The other idea is 3D XPoint paired with quad level cell SSD’s. Maybe could do mixed system with some arrays hybrid flash and 3D XPoint and other arrays hybrid flash and HDD.

Network attached storage: combined file+block, with Fibre Channel over Ethernet and NFS.

RAID6, RAID5E, RAID3, or RAID10. Not RAID1, RAID2, RAID01, RAID100, or RAID-DP. Maybe RAID5 nested in JBOD. RAID4 for smaller arrays and RAID6 for larger arrays.

Dynamically extendable monolithic with procedure call for local OS or on host, and multi-server microkernel with message passing for distributed single system image. Another idea is multiple monolithic kernels on top of an exokernel.

Local procedure calls and remote message passing. Synchronous message passing between closely coupled nodes, asynchronous message passing between disperse nodes.

Microkernel for host of type II hypervisor, and monolithic kernel for guest.

In a massively parallel processor array, one RISC massively manycore processor per node.

Non-technical:

Tiered enterprise software licensing: open-core with permissive or copyleft license (the best are three-clause BSD, Apache 2.0, Eclipse Public License 2.0, and LGPL2.1+) and proprietary commercial version(s).