
If "fair and square" means fracking your partners, then yes
Interesting. This is not quite what I remember. First, IBM and Microsoft convinced Lotus (and also Word Perfect, the other "big kahuna" of the DOS PC era) to spend all their development cash on OS/2 versions of their products. As good partners, both did just that - having ports running on OS/2 by 1989, but without the Windows-style interfaces. Secondly, IBM and Microsoft divorced, followed by the Softies announcing Windows 3 as their only strategy, coupled with their intent to move Excel and Word to that platform exclusively (no OS/2 versions). This left Lotus with a hard choice - stay with IBM and OS/2, or move to Windows 3 and partner with Microsoft, which had the leading competitive product. Having by that point built a working version of Lotus 123 with full OS/2 Presentation Manager (PM) capability, this was the equivalent of telling Lotus "please throw out 3 years of development effort and start over."
Remember that the OS/2 version of Lotus 123 COULD NOT BE EASILY PORTED to Windows. OS/2 software was based on an assumption of a pre-emptive multitasking OS, which Windows 3 was not. Also PM and Windows were quite different on the UI as well. So not only would Lotus have to change the UI over from PM to Windows, it would also have to rework the core code to work under Windows 3 w/o proper multi-tasking. Once it became clear that Windows was going to be the customers' direction, however, Lotus faced the inevitable and built a Windows 3 version, but only after MS had built a big head start convincing customers to migrate to Windows 3 with Excel and Word.
That was when the final blow was applied by Microsoft. By the early 1990's, both Lotus and WordPerfect had working versions of their flagship products running on Windows 3; two years late, but good products. This was when Microsoft announced "Microsoft Office", meaning that they were giving liberal allowances for competitive upgrades from either Lotus or WordPerfect to get both Excel AND Word for Windows. Hard for the competition to match that, given their overall higher price, their need to recover both the OS/2 and the Windows development investments, and that they were by then cash starved because of loss of market share to Microsoft.
Was Lotus "lazy"? No. Did it put too much trust in its partners IBM and Microsoft - decide for yourself. Do I blame Microsoft? Of course not - taking strategic advantage of your partners appears to be how all tech companies operate. Microsoft has just been so much better at it down the years.